Replacing an oil boiler with an air-source heat pump: Why, what and how

We replaced our oil boiler with a Daikin Altherma 3 H HT air-source heat pump. It wasn't to save money, it wasn't to save time - so why did we do it, and was it a good idea?
Sources cited in this video:
www.boilerguide.co.uk/compare...
www.greenmatch.co.uk/heat-pum...
heatable.co.uk/boiler-advice/...
www.homebuilding.co.uk/advice...
www.gov.uk/apply-boiler-upgra...

[@michaeldepodesta001]

Michael: Thank you for the video: I don't think your efforts are futile - they represent my own motivations too - and those of many others. I hope you and your family have a warm and happy winter. Michael

[@SteveRichards-zr7xz]

Good video. We had an oil boiler and tank was getting on (and replacement could not go in th esame place...) and the combi boiler was about half way through explected life. Like you we wanted to remove fossil fuel so decided to use some of my pension lump sum for solar panels and a battey. We were exploring an electric boiler with our planned solar planels. One call resulted in a 40 minute detailed exploration of ASHP and after a couple of other quotes we went with our first contact. As a bonus the same company could do the solar and battery - Install was not painless. All but three radiators were replaced with bigger units. We had to cut a hatch in the wall of our bedroom to get the water tank in. Overall the installer was excellent, the crew were hard working and nice to deal with. Result? We paid less for our entire electric in 2023 than we paid for oil in 2022!! The house stayed as warm as it had with oil. The hot water supply is better than the combi. The system is much quieter than the boiler. Over all very impressed. - Electric use during the two longish cold spells in Dec 2022 and Jan 2023 (several days below zero and down to -9C) was a bit scary - we peaked at 84Kw one day and the unit was obviously working really hard below 5C but it coped. During the late spring through to a few days ago (mid Oct) the unit only ran to heat water - two approx. 40 minute runs at 2am and 2pm GMT and only used approx 1.5Kw each day. We also have a electric boost that runs for a short period every Sunday early AM to prevent Legionella So - if you are on oil, an ASAP is great - esp. when supported by a good solar setup. Things to consider... - the external unit needs some space behind (c. 250mm) it as well as infront - it blows out cold air - pleasant on hot days, but very cold in winter - we think it killed one of our plants during the winter cold spells. - The closer the unit to the hot water tank the better. - The water tank will need to have the correct heat exchanger and insulation. - There are quite a lot of electrics- programmers, wifi etc that need space... (our system assumed you have wifi). - You need the radiators and hot water tank to meet the 'rules' to get the grant. Whilst our loft was rated OK I did double the loft insullation and had a hard look at any potential for drafts.

[@michael_bird]

Great post, really detailed - thanks for sharing Steve

[@snowbirdy00]

Great, honest insight from a relevant perspective. Will deffo be watching this again when it’s time for us to review our boiler. Thanks V

[@barryinkpen6026]

I went down a similar road a few years ago and started the process by lowering the temperature of the water my oil fired furnace pumped out to my in floor system. I built a controller that kept the water around 40 to 45 degrees C which turned out to be good enough for even the coldest days in eastern Canada. After a couple of winters I pulled the trigger and installed a 50,000 btu, mono bloc system that provides heat to the house and preheats our domestic water. It runs from 40 to 50 degrees C. It is cheaper to run and we have the peace of mind of not worrying about oil leaks, and of course it is a "greener" solution. Lower temperature water supplies can work in many places if you increase the surface area of whatever system you're using. We went to mono bloc to keep all the noise outdoors and we didn't need a contractor for installation due to the sealed system.

[@TheMysteryPicker]

Great presentation style Michael, good to hear your story. It'll be good to hear an update in a few months into the winter to see how its going. All booked for a survey for mine coming up soon 👍

[@michael_bird]

I think I’ll do an update after the winter with some details of how much it cost to run. Good luck with your install!

[@chrisallen6010]

We have a Combi boiler and last year I started preparing and testing for a heat pump. Dropped our flow temperature to 40 on the radiators and 50 on the hot water. Strangely, the house felt more comfortable over the winter, we were running the heating for longer but we were using about 35% less gas to heat the house to the same temperature on the thermostat - though, last year was a mild winter. This year, I'm dropping the flow temperature even further to test again. I feel it's better to understand now rather than when the boiler needs replacing. Thanks for the video. There are plenty of videos starting to appear where heat pumps have been installed terribly by individuals who either didn't understand or didn't care. If you drive you car down the motorway in 3rd gear at 90mph, the experience won't be great!

[@michael_bird]

This sounds like a really sensible idea

[@joewentworth7856]

We did this before getting a heat pump and it helped give nice confidence it would work at a low flow . It also pointed out which rooms needed a larger radiator but also which ones didn't. Which saved money over what the calculations said it needed. The msc calculation appear to overestimate from my experience. So having actual energy measurements is great. See michael podesta s rule of thumb. He has a video on yt. Maybe as 'protons for breakfast' divide your anual gas use in kwh by 2900 I think and this give the heatpump kw power you likely need. I found this to be a better measure than the msc calculation. Good luck .

[@chrisallen1782]

@@joewentworth7856 That's good to know. Our Greenstar 35cdi has a stated flow rate of 750 l/hour (brand new in ideal conditions no doubt!) so I'm also interested in the effect of having a more constant and immediate temperature in the radiators if a heat pump can deliver over 1200 l/hour. Sometimes, it can take up to 20 minutes for some radiators to start to get heat and around a further 20-30 minutes to actually get warm. This is with a mix of 22mm and 15mm piping, mostly copper but some plastic.

[@joewentworth7856]

The higher flow will make a difference i guess. But heatpumps are not great for quick heat. There party piece is running low and slow with massive efficency. If you do need to fluctuate the room tempratures you do need a little planning. But most say its more efficent to maintain a fixed temp 24 7 running the pump as lightly as possible. You can turn the temp down a couple of degrees at night. For comfort but start warming it back up an hour ahead of when you need it. Ours heats up at a rate of about 2 degrees per hour.

[@desmondbeattie3954]

Sticking to my oil fired condensing boiler.

[@Lewis_Standing]

Really good video, hope it works out well. Looking forward to an update over winter.

[@markmurphy7301]

Great video. More please through the winter. Would be very interesting to see the updates. We have an air source heat pump too, but in a new build. Heading into our 2nd winter and still tinkering. Have to say it did a great job last year, cost and comfort we can't fault. Good luck to you.

[@uksupporter8867]

They are a rip off

[@johnfreshwater3790]

Excellent idea and video we are like you and live in a oil only village everyone told me i was mad 3 uears ago fitting an ashp and im glad to say i am happy we did. Whole better experience with comfort levels and no worrying about ordering oil. Freed up space in the garden. You are right about keeping heat in although dont be put off if you have a old house ours is 220 years old and solid stone. Still very happy with the running costs

[@dj0men666]

Did you install without the grant then? How would you go on for heat and hot water with a powercut in winter?

[@johnfreshwater3790]

@dj0men666 we get RHI which was pre the Grant. And as for a power cut your oil boiler has to have an electric supply the same as any gas boiler. The only thing that doesn't is a Rayburn or AGA that has a vaporiser which we did have a oil Rayburn but I also converted that to electric as its half the cost to run as they are very in efficient on oil

[@dj0men666]

@@johnfreshwater3790 ive got a h2 panel that links up to my log burner. They do a h5 for link up with heat pump. Good bit of kit.

[@hisroyalblueness]

We’re in much the same boat. We live in a little Shropshire village where there’s no gas and we recently had our perfectly functioning oil boiler removed and an air source heat pump and Mixergy cylinder installed. I mentioned this to the engineer who used to service the oil boiler and he said, in all seriousness, “keep hold of it and I’ll plumb it back in for you when you realise that heat pumps don’t work”. 😂😂😂 We’ve never been warmer and costs aren’t too bad as we’ll save the best part of £1000 pa by not filling up with oil each year, and have a 4KWp solar array, which helps. We’re having another 10kWp of solar installed later this month and 28.5kWh of battery storage so that we can further address the costs in use. The unit we have is a Grant Aerona 13kW and it runs whisper quiet. If you open the door and listen carefully you can hear water running through the pipework in the cylinder cupboard, when the heat pump runs, but you need to go outside and stand right next to the ASHP to hear the device itself.

[@eddyd8745]

That's some solar/battery arrangement that you'll have!

[@richardlewis5316]

Actually that was a sensible back up plan as the old oil boiler was costing nothing to keep apart from a bit of space. The oil tanks had to go anyway. I have designed a dual system where some radiators are heated by an air pump but others are still heated by a combi boiler so if the outside temperature is low I can get the house warmer quicker.

[@MrKlawUK]

nice video. Worth pointing out that boilers are often 70c for legacy reasons. with a condensing boiler you can often run it at 45-50c also if your radiators are big enough. It can be a good way to see if your house is ‘heat pump ready’ and also save money by using less gas and staying in the condensing zone more often

[@michael_bird]

Great tip!

[@Roedy_Coedy]

This is what I did last year, I ran my flow temp at 45c, had the boiler running 3x as long (due to the lower temps) and ended up saving slightly on the gas use the year before but was FAR more comfortable. The only time it was an issue was when we had a week at -7c the living room was too cold. I've changed that radiator to a Double panel now and trying again this year. May even try 40c (but knocking it back up to 45c if we get a crazy week again).

[@maidsandmuses]

If it is a _system_ boiler (not combi-boiler) it will need to be set to 68-70c because it also heats the hot water tank. If you then switch to an ASHP you will need to find a different way of heating your hot water supply (likely electric). It will lower CO2 output, but depending on your hot-water vs. heating use ratio, it may not _necessarily_ save much money.

[@Lewis_Standing]

@@maidsandmuses aren't some system boilers fancy and can do two different flow temperatures for hot water and heating? PDHW?

[@maidsandmuses]

@@Lewis_Standing Yes indeed, but not all are set up that way; if it was a boiler refit to an older cabled installation the boiler will only receive an on/of signal, not a hot water vs. heating signal. Then it is just set for 70c since it doesn't know the source of the demand. Newer systems can be set up with two temperatures, yes.

[@edalbagem]

Well explained! I run an air source heat pump myself in Sweden like more or less everyone else here. I find it difficult to understand the scepticism whether it will work or not in the UK. Worst case there might be a need to add or increase the size of a radiator or two in order to compensate for the lower temp radiator water. 👍

[@georgebarnes8163]

I am in the UK and am using one Air source and one ground source heat pump, both are solar powered providing all heating and warm water FOC, the air source pump doubles up as air con in the summer, on average I am getting 3 kW of heat output per 1 kilowatt input

[@Jaw0lf]

I am now subscribed and wish you all the best in growing your channel. I have been down the same road and all your comments at the start really remind me of my thoughts. We are also in a small village, had a bulk LPG boiler, storage tank get condemned (now in wrong position) after 45 years in it's position. Boiler also was older and parts difficult to get, so we jumped to ASHP and replaced all radiators due to them all being very old and rusty in parts. We initially had solar, then doubled the solar and added a powerwall. Then came the EV and ASHP a year or so later. We have not been cold and in fact maintaining a constant 18c or 16c overnight the house has felt warmer. We used 3,333kWh in our first year for our 5 bed detached house. A year after we managed to get our Cavity wall insulation that had broken down and was as good as none, replaced and we are now saving about 30% on our usage. The new water tank has a lot more internal pipework thoughout the cylinder to heat the water at a lower flow rate. Same thing as the radiators having more fins.

[@tonyking2030]

Very helpful video. I think for me, living in a remote Scottish Glen, I don’t want to take the risk of being reliant on one source of power to keep warm, especially when power cuts are quite normal here! Also being an older traditional stone building, even though double glazed & insulated to the best of my ability, the heat loss would be too much for a heat pump to run on a budget I could afford!

[@waynegazard5038]

Othe than solid fuel you'd require electric to run a gas/oil boiler be it 3amp ,in your case would invest in small generator, so you could still run APump be it on fossil fuels as indeed the electrics being produced by.

[@Displays.1234.]

I have come across quite a few heat pumps and the radiators just only get warm it's been complete rubbish... Even heatings engineers have told me the same story....

[@dorsetengineering]

@@Displays.1234. The radiators are supposed to be 'just warm'... I'd suggest it's your education that complete rubbish.

[@Displays.1234.]

@@dorsetengineering warm radiators that do not heat up the room absolute rubbish...

[@waynegazard5038]

@Lockkhanup think people missing the point you require a massive surface area rad to equal prev rads and using electric to reach h/w requirements great if you have room for a massive storage vessel evs and immersion heaters added onto a struggling grid what could possibly go wrong .

[@Mrcricketman34]

This is my favourite video on the internet. All our love, Ron and Babz

[@Dale-11]

Really 😂😂😂

[@GlynHudson]

Great video, I've got an ASHP in a 200-year-old solid stone house, and it works fantastically, it's been cheaper to run than mains gas and more comfortable since the house is a nice consistent temperature

[@timclarke8565]

What upgrades did you do to make the ASHP more efficient? Or did you previously have a baxi back boiler?

[@robtt997]

So what did it cost ? Did you have to upgrade your insulation and what did that cost ?

[@robtt997]

Just remember these things last about @8 years . A lady in our village had her Husky replaced ( it could not be mended as no spare parts available ) and it cost her £8400 for a new Mitsubishi unit including the fitting.

[@joewentworth7856]

@@robtt997 that's a fair warning. Buy a brand who are going to stick around. Vailant units are definitely repairable and have spare available... but same as buying cheap 'single use ' combi. It could also be due to the lack of f gas techs about. If you thought there was a shortage of heap pump installers. Try to find someone to re gas a unit. It will change as the market grows though.

[@terryjimfletcher]

@@robtt997 A well maintained ASHP will last 20 years. We've been in our house 26 years, and we are already on our THIRD gas boiler, so gas boilers are no different. Whilst researching ASHP I've never heard of Husky in Europe (inc UK), so that must say something about that brand. Vailant are a massive European company, and as @joewentworth7856 said they're repairable, plus suited to our climate. One thing I would says is to get a proper survey of your property by a HeatGeek trained installer. It should take at least 2 hours. If any installer finishes their survey quicker than this then you might want to pass on their quote.

[@michaellupton1593]

Really informative Michael, thank you for pulling it together...we were in a similar situation a few months ago, we live in a very rural location dependent on oil, coal and logs for heating...oh and solar panels for everything. Our oil tank started leaking so we looked into air source/ ground source heat pumps, our trusted and reliable heating companies basically persuaded us against the idea. Friends and neighbours regurgitated the horror stories..so we just replaced the oil tank then a few months later our oil boiler required replacing, not unexpectedly to be honest. I tried to get quotes from companies but none of them appeared very interested or trustworthy. There clearly is a problem with availability of reliable installers so we decided to leave it a few years to allow the market to mature. Perhaps we have been too cautious...our home is a large detached 300yr old stone house, double glazed with loft insulation but it’s still not a well insulated building. As you say the tales of woe of other installations definitely scared the horses with us. We will try again in a few years when this boiler/tank breaks or if the price of liquid gold becomes unaffordable.

[@mrradman2986]

I live in a 300 year old former farmhouse in N Yorkshire. When I first moved in it used an LPG system which over time became very expensive. We switched to an oil system as no mains gas in the village. This was OK for around 12 years but the steel oil tank which was well painted and mounted on pillars showed signs of corroding at the bottom and was going to need replacing along with the boiler at some point. After some research I opted for a wood pellet system having an old shed which was suitable to convert into a 3 ton hopper. The boiler sits in a cellar and as a bonus the North facing room above is now warm in the winter. The system works very well after some teething issues and didn't require replacement of radiators etc which would have been the case with a heat pump. It is the best method of heating the building out of all three we have used. To supplement it we have a solid fuel cooker/ boiler in the large kitchen which in which I burn recycled wood briquettes plus some logs. This proves invaluable during not infrequent winter power cuts.

[@ColinWatters]

Your install looks very neat. Always a good sign.

[@billycan8852]

Great video I have the same heat pump as you . And it’s my second winter,and we love it .

[@st200ol]

Where I am in the UK it’s been so warm this winter that a system like this would be perfect, so much outside air heat to reclaim, 11 degrees yesterday for example. As more of these are installed the installers will get better at it too. Thank you for being a guinea pig for all of us.

[@michael_bird]

Yep, worth saying when it has been really cold outside the heat pump has been able to keep up

[@jimmysrealcooking554]

Great video. Extremely clear and fun.

[@michael_bird]

Glad you enjoyed it!

[@RpR_Makes]

Michael very informative thanks. You should make more videos as you have an excellent presentation style.

[@DeneF]

Don't know anything about curves but our system is used manually as and when. Just had the wall insulation done, also the solar but no battery. Swapped our radiators to bigger ones. Will see what the winter brings? Thanks for the video and good luck.

[@erics2147]

I was in exactly the same position two years ago when cracks appeared in the oil storage tank three weeks before Christmas. The oil fired boiler was at least thirty years old and, although working perfectly, wasn’t likely to last much longer. I was very unsure about a heat pump’s ability to keep the bungalow warm in it’s rural setting so I decided to go with an electric “boiler” which is like a sophisticated Emerson heater which heats the water to the same temperature as a oil/gas boiler and was a straight replacement for the old oil boiler using all the existing pipes and retaining the hot water cylinder. The installation took two days with a total cost of £5000. The system (made in Italy for many years) 14:45 uses 13 kw when heating from cold but drops in stages heating the radiators very quickly bringing the bungalow up to 22 degrees in an hour. The running costs are fairly high but not when compared to the old oil system and the relatively low installation cost means there is already a considerable saving compared to a heat pump. There is also an existing array of 16 solar panels at the property which helps reduce bills. After two years no maintenance has been required and the whole thing is controlled by a Nest thermostat which I access via my smartphone. The old Emerson heater still works so I tend to use this for hot water particularly in the summer when the solar panels produce enough power to cover its electricity consumption in the middle of a sunny day.

[@JohnWilkins-pc5ji]

Hi, we are currently in a very similar position to you with the oil etc and would like to go to an electric boiler. Sorry for asking but how much per month does the electricity cost?

[@erics2147]

@@JohnWilkins-pc5jiHi - I was with SSE but they have been taken over by OVO and only show consumption for the last six months which is an average of £118 per month (not including standing charge or VAT. But this is for a detached 3bed bungalow with solar panels so consumption will vary wildly depending on the property. The system does use a lot of electricity but the cost is roughly similar to the old oil system which used £1,000 to £1,200 worth of oil each winter.

[@wobby1516]

We are about to go down a similar road as you, the only difference is our house is just 10 years old and my new EPC is A106. Almost the highest short of passive. I’ve opted to have Octopus Energy install our heatpump mainly because I trust them to do a professional job and of course have the backing of a huge company, with a Which rating that far exceeds all the others. My instal after the £7500 grant is just £600 however if installed before June next year Diakin have offered an extra £300 discount so my final cost is just £300. It’s a no brainier for us. We also have solar and 27kwh of battery storage so we’ll be all electric and that’s another saving of £100 per year standing charge on gas. For those who no doubt will say that I’ve had the cost of solar and batteries, yes and no doubt will say how long is the pay back. My answer is, if I were to sell, my house its worth more by virtue of the solar, battery and heatpump plus I’ve substantially reduced the running costs of our house, which I have calculated as near 5% return on my investment, which otherwise would be earning a lot less.

[@Swwils]

EPC rating has absolutely no relevance to passive haus.

[@SlowhandGreg]

Did an extension last year which is double insulated with underfloor, this year been pulling up the ground floor to extend the system and double insulated the floor at the same time. We have a mixed system with radiators upstairs, i specced a large hot water tank that was thermal solar compatible which will be installed sometime in the spring once i've finished all the decorating. The water tank acts as a thermal store Underfloor heating is between 20-40% more efficient depending on your heat source and the levels of insulation, you can run a mixed system no problem we did the conversion downstairs a room at a time once outside the new part. The house is a 1935 and needed some TLC including new windows and replastering

[@paulsweeney5642]

As mentioned many times keep us posted with your experiences 👍🏻

[@rjjones50]

Loved it. Very honest. I liked that you provided the sources of the videos you showed. I think you needed a new water tank for your hot water storage because the water flowing into it to heat the water has a lower temperature than from an oil or gas boiler, so maybe there is a bigger coil, but I am not an expert in all this.

[@michael_bird]

Yeah I think you’re absolutely right about the need for a bigger coil

[@boblyall]

Nice video thanks! We’re swapping our old gas combi system for an ASHP next week 👍

[@michael_bird]

Good luck!

[@brucejoseph8367]

I hope it works well as it's been an expensive project. Best of luck to you!

[@bernardmills4575]

Thanks. That was very helpful.

[@ForTheBirbs]

Hi from the other side of the world in Sydney, Australia. Heat pumps have been used here for pool heating for decades. Air conditioning split systems aka reverse-cycle aka heating and cooling and been inverter drive for a long time also. While we don't need the radiators etc like the UK, gas hot water systems are starting to be replaced by heat pumps too. With the enormous penetration of solar panel installation and now batteries, all part of the energy revolution. Cheers

[@AnthonyFrancisJones]

Great - thanks for this. We have solar but are considering the next step!

[@johntisbury]

Super video thank you. I'm sure you will be fine this winter. We have just had ours installed in July of this and know how long the installation process it. Like you I initially had a buffer tank, but soon had it removed. Our system is microbore and the buffer tank was put in as an assurance item. However, it does impact efficiency and increases noise. You may find your system will actually work without a buffer. Fewer and fewer installers are fitting them now as they learn more and more about ASHP installs and how to improve efficiency. Perhaps something to think about in the future. One by one we are making a difference by moving away from fossil fuels. The hot water being poured into the ocean, using your analogy, is reducing day by day, week by week as individuals move to hear pumps. It's still early adopter territory in the UK but it is picking up speed rapidly.

[@CaptainProton1]

Only it's not reducing as China adds a new coal fire plant every other week and we put out less than 1% of worldwide contribution. But we are very good doing our best to make life very expensive and miserable for those with less money on this journey. I have 2 heatpumps air to air, 40 solar panels and 32kwh of batteries plus an ev but I do not agree with the hysteria of 'we're all going to burn in 5 years) have been hearing this for 30 years....and no it was not the hottest summer on record in UK :)

[@jimthain8777]

@@CaptainProton1 Actually it does still reduce, as China, or any other country was going to do what they were going to do anyway, so their increase was already in the works. While decreases anywhere are a new thing, and not loved by the oil who own us.

[@burntre1]

@@jimthain8777so it doesn’t reduce then, just an insignificant offset from the rest of the industrial world who continue to laugh at us.

[@glynmoore3730]

15 or more years ago we used to heat a swimming pool with an air source heat pump and it worked brilliantly, and mostly run through the night on Economy7. The pool was covered by a poly tunnel so it drew warm (or even hot air in the summer) from the poly build, and expelled the used cold air from the back to the air again. Never seen anyone else do it, but why not fit a green house over the air inlet side, with another positive that it would protect the unit from the elements.

[@clairelegresley7537]

You’d need to be careful the greenhouse didn’t start becoming like the inside of a fridge with less and less energy for the HP to extract and not enough solar gain, and/or air flow, to replace it? More likely to be an efficiency only in summer but a much bigger inefficiency in winter?

[@marquisdemoo1792]

Really great explanation. Unfortunately I live in a 13c listed building, which is a nightmare to insulate, so not for me.

[@ianferguson3543]

We have Oil. We bought a new oil boiler when we moved in. Then fuel prices moved and the oil became closer to gas so we are happy. Here in Scotland we need a decent amount of heat in winter so I just can't see how air sourced would help and electricity isn't that cheap either.

[@joewentworth7856]

Although I think the Scottish grants for HP are far more generous than England,

[@user-ii8bz7mr8f]

An excellent explanation. We would like to replace our gas boiler with a heat pump, but the process has been ruled out due to the cost of having to rip out all the 8mm heating pipes, and a brand new 2000l pressurised hot water tank. We have solar panels and batteries, and they heat the water for 7 months of the year.

[@ColinWatters]

Can you retain the 2000L tank as a buffer?

[@Richardincancale]

I did the same thing this spring for the same reasons and using the same Daikin system! So far looks to be about half the cost of running on oil. Here in France heat pumps are common, so no raised eyebrows!

[@michael_bird]

That’s good to hear!

[@eddyd8745]

Gas is so much cheaper than electricity in the UK so it's difficult for most people to justify (financially at least).

[@Richardincancale]

@@eddyd8745 Gas must be around 4 times cheaper per kWh to be equal to an ASHP, allowing for a SCOP of 3 (minimum) plus the inefficiency of gas boilers - say 10-15%. With oil the current price is ~1.35€ per litre and each litre yields 10.5 kWh before inefficiency of the boiler - typically 15%, i.e. 9 kWh net. So ASHP will use 3 kWh of electricity at COP 3 to make 9 kWh of heat, costing 3 x 23.5 € cents (prices just went up by about 30% here) - about 70 cents. A little extra is not ruining our climate!

[@robevans8625]

So how much was the install cost including the loft insulation and raising the floor height?

[@MSGaddicts]

Thanks for sharing

[@juliandclarke]

Great video. I’ve had the same ASHP since April 21. Cost me the same as oil boiler we’d had installed 8 years previously. No radiator or pipe work changes. I’ve achieved efficiency/SCOP of 4.06 for November. I’m running the weather compensation curve. I talked to ten installers. Got 6 quotes before I chose my installer. All good. Did you go for the 10 year fixed price service/warranty from Daikin? Was it not possible to site the exterior unit closer to your property?

[@ianbeck5897]

We moved in to our house 18 months ago. Again, no gas in the village and we were on oil. Just like you, our oil tank was condemned the moment we tried to fill it more than half full. I contacted a few renewable heating companies and the one who was interested started by asking if we had three phase? With the size of our house he thought we would need three phase! We don't and it would prove expensive and slow to get it fitted and three phase suggests lots of electricity being needed, at least to me. In the end we bought a new oil tank, bunded and 2000L in volume. We got the boiler serviced. The engineer told us to hold on to it because it was a good unit and fine. Phew! Our house has dual manifold hydronic underfloor heating and a thermal store, admittedly approaching twenty years old. We have no radiators and a couple of our rooms have wood burners. We also have solar on a FIT, a payment for wind turbines (almost 2 miles away and not an issue) and have since added batteries. We now run Octopus Agile. I am hoping that the FIT, the savings with Agile and the turbine subsidy will just about keep us breakeven on electricity cost. We get through about 2-3000 Litres of oil a year. If I buy it when it is cheap, it isn't too bad, especially for our house, close to 3500 square feet. The calorific value of oil vs electric heating, even taking COP into account, doesn't necessarily make ASHP a no brainer - especially if the existing infrastructure needs to be changed (radiators upgraded, for instance). The time of oil purchase needs to be considered, 50p/litre in the summer is a lot better than 90p/litre in the winter and that plays toward keeping oil. The other thing is the type of house. A modern thermally efficient house is a much simpler proposition that one like ours : part cob, part stone, part cavity wall - at least we have low-E glazing and decent roof insulation for the most part. It's a whole different matter if the building is listed and very drafty! I sincerely hope that your move to ASHP plays out well for you. Were our boiler to pack up I would seriously consider a heat pump again. By then, hopefully, the installer knowledge base will have improved and prices may have dropped a bit more.

[@31770]

Thanks for putting together your video. I'm looking forward to seeing how you get along. I'm sure nice and snug all winter. Would be really interested in knowing what temp the radiators actually get to if you have any way of measuring. I know the flow temperature low, 40 or so - but I'm curious what actually the rads actually reach.

[@johnbb99]

IME [we had an oil boiler replaced by ASHP 2 years ago, modern house, ] is that the bedroom rads don't get noticealbly warm, but the rooms are as warm as before. it's the constant low level feed that does it. *When properly planned* ASHPs are great.

[@occamraiser]

They will be 20 to 30 degrees cooler. And give of proportionately less heat.... this can be countered by more flow (if you don't have micro-bore pipes or small radiators) and by running them for more hours per day. My central heating pipes are set in the walls and are micro bore. I would need to rip them out and replace all my plumbing and radiators with bigger ones, and OMG, the cost of replastering and redecorating. A heat pump would cost me more than £20k.

[@johnbb99]

@@occamraiser You may be right about the microbore being too small, but not necessarily. Eg our bedrooom rads are fed with 10mm (o/s diam) pipework, and only get noticeably warm when it's actually freezing outside. The rest of the time they warm the room without getting warm to the touch, just on all day. A survey of your house and system by someone who knows how to do the calcs correctly might say you are ok.

[@UntrainingUltrarunner]

Thanks that’s useful!

[@MagicianMan]

You needed a new Hot Water Cylinder as the coil inside that transfers the heat from the ashp heating loop into the Domestic Hot Water needs to be larger than a standard cylinder (due to the lower operating, or flow, temperature of the ashp). A good way to think of it is "you are increasing the size of your radiator inside the Cylinder"

[@terryjimfletcher]

If we have a 145litre HEAT-STORE would this get around this issue? The mains pressure cold water runs up through the "water jacket" in a big coil, popping out at the top side of the tank piping hot at mains pressure (we wanted mains pressure showers in our dormer).

[@occamraiser]

Also you probably need bigger radiators and may need full sized pipes if your heating uses small-bore pipes.....like many houses from the '80s onward have.

[@paulgoffin8054]

Most likely reason your water cylinder needed to be replaced was the internal coil of your old one didn't have enough surface area to transfer enough heat at the lower temperature. It's effectively an internal radiator upgrade.

[@michael_bird]

Yep, I think that was it!

[@johnbb99]

Also since the temperature in the tank is lower, you need more of it to acheive teh same bath or shower [etc] temperature [you previously mixed cold with the hot, of course]. This was the reason in our installation.

[@Username-yh5du]

Great video, thanks for sharing. Owned my hitachi heat pump on new build for 1 year. Very expensive to run, about €500 per month 1700 sqft, temp set 22.5c during winter. I just signed up to cheaper night time rates and asked the service guy could he programme the hp to activate from then , but he advised me not to, he gave me some convoluted reason not too, but I noticed you said your hp is timed for nighttime use.

[@michael_bird]

Yeah, it’s just the hot water that heats at night - so 2-4kWh done on the night rates. In reality it’s running 24/7 so a good chunk of the heating is done at the cheaper night rates anyway.

[@anthonyhill8061]

nice video chap.. i just order mine to day..

[@michael_bird]

Good luck!

[@JurassicJungle]

Brilliant video, you should call it something like heat pumps "Untangled" (you can thank me later). I am really interested to see how you get on with your HT pump to replace oil as we have taken a leap of faith to cut off mains gas and go with a Dakin LT ASHP. We have to be fair ripped the house appart to install underfloor heating and insulated as much as we can (if only I could get my builder to understand insulation and airtightness). We have also added solar and battery, we expect the ASHP to cost more in winter but hope that solar and battery will help balance that cost. The one thing you dont call out in your commentary is the difference in cost of electricity and fossil fuel. It does make me angry that ASHP are quoted as 3X more efficient than fossil fuel, while this is true electricity costs 3.5x more to buy. So if you don't get a SCOP of around 3 or more it will be more expensive than gas.

[@kenbone4535]

Great video, but whould like to know more about the hydronics, also those valves on the back of the heat pump need to be lagged. Curve settings look good. Ive been installing for over 15 years at worked at Daikin for 4 1/2 years.

[@johumm455]

excellent presenting and explaning! how can you have just 150 subscribers ?

[@southwestsellers5475]

Nice video. We had a 6Kw ASHP installed in March 2023. Renovating a 1930s bungalow so had under floor heating installed as well. Would advise anybody considering installing ASHP that they can use a lot of electricity for heating - we averaged 22 units a day over the early part of this week when outside temps went down to 4 degrees for a couple of nights. We knew this before going down the route of an ASHP to replace an ageing gas boiler and have had solar panels and storage batteries installed.

[@joewentworth7856]

We have a 7kw heat pump in vicotorian mid terrace (with loft and rear extension so some improved insulation) in bristol and during those days we used 5 to 7kwh per day. Obviously you house and weather will be different but I would not just accept high usage. A new system can be dialled in to improve efficency. Primarily by changing the flow temprature. Or the weather compensation curve. Essentially try a lower temp. If the heat pump can't maintain the desired room temp then turn back up. Most engineers will set it to a temprature they are confident will work. Its very unlikely to be the peak efficency. Have a Google for heat pump forums there are lots passionate knowledgeable help out there.

[@Lewis_Standing]

Be interested to see what flow temperature they've designed for and the SCOP you're achieving. Those 22kwh could be making 88kwhs of heat (brilliant COP of 4) or 66kwh of heat (meh COP of 3) or performing much worse. So id echo Joe above and see how you could improve things

[@johnbanks8065]

@@joewentworth7856 I'm also in Bristol with a Victorian mid-terrace, original attic room (will be looking to upgrade insulation as my refurbishment progresses) and large rear extension, so I'd be interested to know a bit more if you don't mind sharing. What size and make of system have you got? What installer did you use? Did you have any problems siting the external unit? My house is only about 5m wide and most of that at the rear is either doors or windows.

[@joewentworth7856]

@@johnbanks8065 We have a larger than usual terrace garden so that made siting easy, (although required 10m of insulated pipe work to be run. it does not have to be sited by the house, it could be sited side on. i don't know about your windows, but it can be sited under them if the sill is high enough. they can be hung above head height on a side return and can go on flat roofs if any of that is an option? have a look the dims of Arotherm 7kw they are all quite similar size. you need about 1m of clear space in front of the unit. shared boundaries can be an issue for permitted development, you have to be a certain distance from them. although I have seen several that don't adhere to this though. i think it relates to noise and they are far quieter than they were, ours make less noise than the neighbours combi flue. I got quotes from Pink heating, stone heating and swift mechanical, all seem to know their stuff but only pink offered Vaillant which has a low environmental impact refrigerant R290- aka propane, rather than r32 which is quite a potent green house gas if it were to leak. but there are restriction to where you can place an r290 unit due to it being flammable. Although no more flammable than the gas piped into your home currently! from memory initial estimate was free and maybe i was charged for a site visit, and this was deducted from the bill when i went with Pink. The install was good. not perfect, insulation of the pipe work was a bit average but i sorted that. the setting i was left with worked well to heat the house, but i think most will tell you to get the best from a HP expect to tune it over the first heating season. i massively improved the COP by lowering, bit by bit, the heating curve (just a number) until it could not keep up with the demand then go back up one step. not difficult but cant really be done on the day of install, and will vastly improve performance and running cost. on the subject of how big a unit you need: kzbin.info/www/bejne/nnTImJuBlpifn68 - this is a great rule of thumb for those on gas presuming you currently keep you house at the temperature you like. i found what my house actually used was 30-50 % less than what the MSC calculations came up with. So i pushed for the smaller 7kw unit, (first quote was for 10kw ) having had temps of -5c last year the heat pump was still over powered. so the unit cost less and running costs are lower than they would have been if the oversized 10kw had been put in. hope that helps!

[@johnbanks8065]

@@joewentworth7856 Many thanks for such a prompt and detailed response. I was considering siting the unit towards the end of the garden (probably about 7m away from the end of the rear extension, then a further 10m to the utility room with the hot water cylinder) but was concerned that would be too long a run for a monobloc system and would seriously affect the COP; did they use something like Mibec pipe for the exterior run?

[@geoffreycoan]

We too live in a village with no gas so had an oil boiler, and it was failure of our tank that caused us to eventually get a pair of LG 9kW monoblock ASHP’s. One thing you didn’t mention is newer rules on oil tank location, it looks like you wouldn’t have been able to put a new tank in the same location as they have to be 760mm from any boundaries and 1.5m from buildings, sheds and fences. This was the big issue we faced, we’d have ended with the oil tank in the front garden not tucked away as it was. Generally pretty happy with our ASHP, coming up to end of year 2. The installers designed it to run at 55 degrees which is not at all efficient. Lots of tweaking, turning on weather compensation, flow temps now around 45 and 48 for hot water and the house is comfortable all the time. On really cold days it can chew through 80kW of electricity which is painful, but this is the extreme and it’s usually 20-40kW a day in winter. But summer it’s 1-2 for hot water so gotta take a year round view.

[@michael_bird]

That’s a really good point, yeah we would’ve definitely had issues with siting the new tank

[@petergladstone4322]

Excellent review Michael. Would appreciate some of your insights as to cost comparison heating with oil vs electrical heat pump

[@colin.d]

Sounds a horrendous experience. We got rid of our header tank when we migrated from a conventional to a combi gas boiler, and don't want to go back to having another header tank installed.

[@Phil-kt6hc]

It was a helpful video - can you please do a follow up video after the winter? Thank you. Oh - looking to switch our house to ASHP.

[@michael_bird]

Yes!

[@johumm455]

as you explained, it costs less energy to warm a space when temperatures are closer to each other. So it might be cheaper to charge your boiler during warmer daylight temperatures.

[@hawkeyexiv]

Nicely presented! We're having our heatpump fitted this week, in near 0°C weather, so really looking forward to being toasty again!

[@michael_bird]

Good luck!

[@pumkineater7219]

We are in Spain (Andalucia) so different to you. We have 2 Toshiba Estia air to water indoor/outdoor units that are run off solar as we are completely off grid. These units provide hot water and cooling in summer and heating in winter through a system of pipes on both floors of our 150 year old farmhouse we renovated. I had the roof spray foam insulated and I injected the 600mm walls with a proprietary product. Both floors were insulated under the underfloor piping and are finish covered in stone tiles. The Estias and underfloor pipes and boiler cost us 15,000€ and solar system 28,000€ in 2019. Our house has 5 bedrooms, 5 bathrooms, very large kitchen, library, and large sitting/dinning room over 340sq metres. As you said, you do need a special boiler as normal boilers do not work with the system and you have to change your mind set how to use the system. We say run it long and run it cheap! Free in our case! Do we regret the money spent? Not at all! Not one regret! We had record summer temperatures this year. Averaging 40°C for most of the summer and our house was a cool 22/23°C during that period! Cost: free! Other people were struggling to keep their houses at 30°C! Cost of air conditioning: 3000€/month! With the increase in electricity here in Spain, our return on capital is now over 7 years. Originally it was going to be over 15 years!

[@JoeRafferty0]

Great video Michael, any chance of a small update on how its went for you?

[@michael_bird]

Yep, hope to get one out in the next month or so

[@over-engineered]

Nice video, clear explanation. Question, does having the high temperature capable unit compromise the maximum efficiency when running it at your 35/45C compared to an ASHP that could only achieve say 45C?

[@michael_bird]

Yes, I think so - I think mine is ‘ticking over’ more than it should but the peace of mind of being able to crank it up was worth it (I hope!)

[@normanboyes4983]

Good video - how many radiators did you upgrade in the house? I ask because I changed seven of ours from Type 10 to Type 22 and sized for lower flow temperatures prior to changing my gas boiler to a Viessman 200 W 4 pipe system. I am currently running entirely on weather compensation all my TRVs are turned to maximum (so they will never operate) and we have no internal reference temperature (room thermostat). So, here we are in a large 5 bedroom detached and the ambient temperature around 7c and the flow temperature from the boiler is 30 degrees (so the boiler is condensing nicely) - the house is uniformly comfortable. It took a few weeks to fine tune the weather compensation to the house dynamics, but it is worth persevering as once it’s done it’s done. At - 2 C ambient the curve will lift the flow temp to around 45C. I did not go ASHP for one single reason - no confidence in the industry. The ASHPs themselves are well proven and efficient absolutely no problem. However the hydronics design within the house is beyond the competence of most of those who are currently installing. It’s like the Wild West out there. Hopefully ten or so years will resolve the industry problems and then - maybe.😉

[@michael_bird]

Just the one radiator, agreed on the lack of installers - we found it a real challenge to find one!

[@Umski]

Sadly there are a lot of boomers out there reading the Daily Mail that genuinely believe the negativity around HPs and hence have it in their minds that they "won't work" - my in-laws replaced their old oil boiler last year - BUT the installers convinced them they needed a 35kW unit - I estimated 10-15kW needed at most 🤦‍♂ Then just to make things worse, they set the flow temperature to 80C rather than the minimum of 65C - wonderful set up for a so-called 90% efficient condensing boiler 🙄

[@Francophil555]

How much did it all cost ?

[@user-tt6il2up4o]

We reaplced our old ASHP with a new one, ripped it out within a year and got a vertical drilled ground source heat pump. ASHP, don’t work when it gets to around zero or even 4, at this point they need to use electricity, as they get to below zero they freeze up and need constant defrosting whilst defrosting no heat is produced. We live in Sweden and most ASHP are being replaced by vertical drilled Ground Source. Add to this the noise whilst it’s defrosting, which can sound like a double decker bus sitting outside, we bought the claimed quietest ASHP on the market. Always go ground source if possible ASHP are no where near as good in any respect. Our ground source drill hole went down 196M, so the drill rig took a while.

[@Martindyna]

Very interesting, i hadn't heard of vertically drilled piping for a GSHP (I've only got s small garden).

[@davekent8193]

Love the video, clear and concise . Is it possible to run the ASHP using our solar panels -does this require more expense rewiring ? Many thanks

[@michael_bird]

Not sure on your specific setup, but ours runs off our Libbi battery and solar system. Battery charged at night when it’s cheap and the heat pump runs off the battery and solar until it runs out of charge/sunshine.

[@user-kw5je3jt8l]

Hi what size ducting do I need to do the same please?

[@chrisskeen3350]

Really interesting video. Impressed by how much knowledge you seem to have picked up during the process. The internal debate on 'cooling the sea' is where I find myself but I'd like to at least internally reflect in later years that I tried. Look forward to the follow ups.

[@anonymouspdg6121]

Nice simple but informative video. 👍 Probably very personal so understand if you don't want to say but as you seem to have had quite a bit of work done, insulation, piping etc, what was the total cost?

[@Pugwash.]

Now I know why a couple of houses near me have had boxes added.

[@gramamg100]

Having just gone through the winter how does the running cost compare? I’m still on the fence I have an oil boiler and keep the bungalow at 22to23 deg in winter. I don’t know if that’s Evan possible with a heat pump and guess the electric cost could exceed the oil costs.

[@NickSeee]

thanks for this Michael, how did your first winter go and do you have any regrets about having gone with a High Temp model now you've perhaps had more time to research or watch all the HeatGeeks videos 🙂? What did you have to pay for installation out of interest?

[@AdrianColes]

Did ypu consider an air-to-air system? We are looking at replacing an oil boiler, but we rarely heat the whole house and have a wood stove to heat the living room (which also proveds background heat to hall stairs and landing. I am strongly considering air-to-air and then infrared for the bathrooms and my office.

[@michael_bird]

We didn’t as when we applied (and I believe it’s the same now), the government grant doesn’t cover air-to-air systems

[@stewartbridge5162]

Very useful. Good that you only had to replace 1 radiator?

[@rabhaw2327]

How long will the ASHP last without it needing repairs or replacement and how much would that cost

[@razvanlex]

Before setting up a weather compensation curve I've preferred to run it manually, meaning I started with a flow temperature and the lowered it until it no longer could keep 24°C inside. And so on for the entire season and realised that i needed between 30 and 36°C for the entire winter. 36° at -9°C. Usually I would need to change the temperature form the app on my phone once every 3-4 weeks when the weather outside was significantly different. But my house is pretty well insulated although I'm using radiators, not floor heating. 135 sqm house and a 6 kW Gree Versati III heat pump. For domestic hot water I'm still using the 35kW instant gas boiler.

[@ice4142]

24 degrees inside!

[@razvanlex]

@@ice4142 Yes, 24-25 degrees is a perfect temperature for us, the same as in the summer. 22-23 in the bedroom during the night to sleep better.

[@Martindyna]

@@razvanlex Sounds like you are from a hot country? My Greek neighbours ran their heating in a similar manner 24/7 until I nagged them to at least set back the temperature at night; they complied to 20 at night. Completely different to me, i've never run my heating at night and when i used to work I only had the heating come on for me in the evening (for the morning I used a dressing gown).

[@razvanlex]

@@Martindyna Not really, I live in Romania. Summer it mau go as high as 35-40°C and in the winter as low as -25°C. In the bedroom at night I keep it a bit lower, 23°C usually, so we can sleep better. We're not wearing "winter" clothes inside, normal clothes, long sleeve and pants. If I feel fine at 23-25°C in the summer inside I think I should feel fine at the same temperature in the winter also. It's not a good idea to change the temperature too much between night and day for the entire house if it's decently insulated, a stationary regime is better and more economic than a transitional regime, especially for a heat pump. A heat pump will work harder with more power and a higher temperature to raise the temperature thus achieving a poor COP.

[@peternorman2563]

Very informative video and many thanks for that. Just replaced my 10 year old Grant oil boiler for their latest model. A very quiet and efficient unit and at an installed cost of £2,000. As ever each to his own but for me oil wins every time !

[@bobstirling6885]

Would be interesting to hear the unit running and have an idea of total installation costs. Then a follow-up giving a comparison of running costs.

[@michael_bird]

I’m hopefully going to do one in the spring

[@topherut]

You have the same system as me, I found everything you said to be correct. Next you need solar and battery. They will provide you with much savings and source for a new video series. Thanks.

[@michael_bird]

Funny you say that, just added solar and battery!

[@topherut]

@@michael_bird Great, when is the first video coming out?

[@michael_bird]

I’ve got another in the works first, but possibly one in the next few months!

[@user-kw5je3jt8l]

What is the pipe run in metres. The Daikin Mono only allows 10metre run.

[@kolitha1]

Thank you Michael for a honest appraisal of your experience so far. What has your experience been with respect to heating, now that it has got cold, and the UK has gone through a very cold snap? We are just about to sign on the line for a new ASHP, to replace our ageing oil system (we're getting a British brand called Grant). Our house was built around 1993 so the EPC does not recommend loft or cavity insulation, but our big anxiety is whether the heating performance will in fact be rubbish and we end up having to use electric fan heaters (expensive!). Would be good to get your thoughts.

[@michael_bird]

Exciting! Good luck. Yep, our house (1930s) was very toasty during the cold snap, plenty of heat and hot water. I think I’ll do another video on my experiences!

[@mikefryer5917]

I live in hope that sooner rather than later this Net Zero madness will end!

[@michael_bird]

Why’s that?

[@mikefryer5917]

@@michael_bird what do you mean why?

[@michael_bird]

Why do you hope it will end?

[@tcblue3095]

So how much did it cost did i miss that bit ?

[@7dayplumbingservices195]

Great video thanks , I am in a process of becoming an installer ( same as you for a green point of view) overall you are happy with the heatpump ( the way it works ) ? Thanks

[@michael_bird]

Yep, very happy - needed a little bit of tweaking over the winter but it’s very much set and forget

[@mrserviceman8795]

Great video really enjoyed just one thing would start looking to find a good service break down engineer for you heat pump as you’ll find that just a hard as you did finding someone to install

[@AndyKennedy]

What a great Collab. Honest, makes me want one of these system so bad. So excited for the future with solar and batteries and the cleanliness and easiness compared to burning stuff.

[@robertdurn2320]

Excellent video. Are you North or South of the u.k. Sorry, you mention the term PRT? Thanks.

[@michael_bird]

Thanks! We’re in the south east.

[@edwardbyard6540]

Great video! Thanks. I didn't think TRVs were recommended for ASHP systems? Everything I've read says not to use them 🤔

[@michael_bird]

I believe it’s a requirement of the boiler upgrade scheme, however you can just leave them all open!

[@tomooo2637]

One critical thing for reliability of the outside unit is that it must be level - otherwise it can result in premature failure of the bearings of the fan resulting in noise. Make sure the base is over specified and really level.

[@ianmcmillan5590]

Great video , thanks. What is comfortably warm ? and how much electricity is needed to run a heat pump 24 hours a day ?

[@michael_bird]

20-22 degrees for us. Energy usage, I’ll report back after the winter!

[@ianmcmillan5590]

@@michael_bird 20 - 22 degrees in a well insulated home is plenty warm enough especially as the heat is available all the time. Really look forward to your running cost calculations next year , again many thanks 😊

[@rtfazeberdee3519]

Heat Geeks are also a good resource for info and installers

[@michael_bird]

100%

[@SimonGreenway]

Please come back in 2024 to summarise running costs and power usage.

[@adrianred236]

You needed a new cylinder because the heatpump flow rate is at a much lower temperature so the smaller heat exchanger in your old cylinder would never have transferred enough heat to make the water hot, so you needed one with a much larger coil. Probably other additional reasons as well.

[@user-uj1mo7iz2n]

I've had a 14kwh Mitzi for 10 years, generally use about 6000kwh over the year for heating and hot water. A major saving is that I have not paid £100+ every year for an oil boiler service, and no smell!

[@thomasschafer7268]

😅😅el is for free.😅😅👎👎🇩🇪

[@nickjung7394]

I reckon I have got the same Mitsubishi 14 kWh as you. Had a problem with leaving the hot water side on all the time. Mitsubishi technical service diagnosed a faulty relay but careful reading of the manual revealed that the software prevented continuous operation. My time switch only allows three timed events per day so I will have to replace it some time.

[@performancedownunder5773]

So what are you doing to ensure the outside unit doesn't ice up in winter.?

[@michael_bird]

It sort of does it itself, not actually sure how - but it creates a big plume of steam every now and again

[@sellma111]

Ashp or a Gshp uses the approx same amount of electricity to produce the equivalent amount of heat you get from gas (cost point of view). At the moment it is a good alternative to oil, but and it is a big but, when the gas users convert to heat pumps along with the EV revolution, the price of electricity will increase as the demand increases. So a heat pump needs to go hand in hand with solar to offset and add some protection from market forces. We are seeing the price to recharge an EV matching or going over the price of petrol to fill an equivalent car now. I have an Ashp however i only run it for the hot water in conjunction with an immersion heater to bring the water up to 60 degrees. It is there more for a back up as we mainly use a stove and a diesel parking heater for the back of the house (uses red diesel). I installed solar panels when the Ashp was installed. No alterations to the rads, the house is cooler without these additional heat sources. Heat in vs heat escape is the main problem and that is so expensive to fix in a Victorian house. Sorry for the rambling comment

[@alanak3210]

I assume you have not experienced a really cold winter yet.

[@davidphalp8371]

What’s your frost stat set at

[@MrKOenigma]

Unfortunately you should take care of all the bushes& trees around there. Or otherwise you will have to clean the heat exchanger surface very often, because leafs could "clog" that up. You can also choose to clean the heat exchanger often, especially in Autumn & Winter, which is what i would try first. Keep an eye on that ❤

[@joewentworth7856]

This is true although the speed of air going in the back is slow its not sucking very hard. On ours leaves don't appear to be an issue. What does get stuck are wind dispersed seeds and blossom. So have a check at those times of year. And keep a cheap dust pan brush by the unit.

[@alexjohnward]

The fan reverses to blow it out.

[@Swwils]

If you need to work hard to keep heat in than the efficiency of your source is even more important. Gas boilers should be run at low flow temps.