Is It Better To Leave The Heating On Constantly? Boilers & Heat Pumps | Consumer Advice

[@HeatGeek]

Join 'Heat Geeks Heating Help for Homeowners" on Facebook for bespoke advice on YOUR specific system.

[@jezlawrence720]

Amazing! ...if only you hadn't quit Facebook in January aaaaaa (This is not a complaint, it's great that you guys are offering that. I'll just have to convince the missus to join lol)

[@HeatGeek]

@@jezlawrence720 just create a pseudo account!

[@davidegarga]

Hi Adam in all your video you never mention to get the power you need for your air sorse heating from your solar panel and battery storage please can you let me know why

[@tu5149]

Can you please do an update now we have to pay over £5k for energy. Thanks.

[@HeatGeek]

@T U this video is even more relevant now.

[@anthonypaynter828]

That is a superb explanation of how to operate our central heating. I have been keeping our room stat at 17oC all night & most of the day, (we are retired & at home constantly). I have been really worried that we were using far more gas than we needed to. But when the heating has been off for 8 or 12 hours, it takes forever for the house to warm up so I have felt that that was too costly so it's nice to hear that you agree. We are lucky to have a well insulated house & a year old combi boiler, our old one had been installed in 1984 when the house was built, but packed up last Christmas. The new one stopped a week ago because of the big freeze, but the condensing outlet had got frozen at the bottom bend. I had to start near the roof with a hairdryer until it had all melted. Added some insulation around the pipe & got rid of the 90o bend at the bottom & all is good now. Very scary being up a ladder to use the hair drier at 80 years old, but our plumber was too busy with emergency call outs. Thanks for an interesting video.

[@QH96]

You're still young at heart 💪

[@gigabyte2573]

YesI found this to be the case too, having a smart meter allows me to experiment with these issues, I found by leaving my thermo at 15c 24-7 I use less gas than turning it off during the night, I found that the boiler has to work harder for a longtime to raise the temperature to the desired temp in the morning, which costs more in gas to raise the temp back to where it should be compared to allowing the boiler to cutin during the night, plus the structure of the house never drops either helping to maintain a steady heat.

[@foppo101]

Same here anthony At 75 Iam not going to sit in the cold.We are both 75 live is to short.

[@spokes1018]

I've followed this and left the heating on, the results have been fantastic! House is nice and comfortable. Heating bill has increased by £197 and getting my house repossessed now. Just kidding, it has improved thermal Comfort and I'm not seeing the vent exhausting loads compared to the neighbours

[@SuperWayneyb]

there’s a word for blokes who don’t leave the heating on 24/7/365, Single 🤘😎🤘😂😂😂😂😂🙏

[@14caz68]

Rich 😉

[@worthy81]

That's a Shit mrs

[@MrPhillipgraham]

Or tight 😄

[@robtyman4281]

Wayne Burgess, Phil Graham - Some people can't afford to have the heating on all the time. Just because you can, there's no need to rub it in peoples faces. There's a name for people like you: arrogant. No one likes a 'boaster' especially when it comes to money. We all know you're having a go at those who struggle to pay their heating bills. Guess you vote Tory then? No surprise there.

[@davewright9312]

There's also one for blokes who can't spell

[@EPPball]

I've taken a different approach. We live in South Australia and the winters here are mild (we don't get snow), but still cold. Our house is double brick, with lots of insulation in the roof and triple glazed windows. We have a large solar array on the roof. I considered batteries, but our main use of power is heating in the winter and so we have 3 Heat Banks. A Heat Bank is a simple device. An electric element is surrounded by a thermal mass (Magnesite bricks). 2 of our Heat Banks are charged during the day by the solar array and give up their latent heat during the evening. The third (largest) heat bank is charged during the night using off peak power and gives up stored heat during the day. The hot water system is a Heat Pump run on a timer, so it only runs during the day when the solar panels are generating power and we only run the dishwasher, washing machine and dryer during the day. The system has worked well for us.

[@beatsg]

Triple glazed windows, I'm jealous!

[@wholeNwon]

Impressive.

[@dancoulson6579]

I think the _worst_ option is to set the heating too high - So that it gets too warm. The bigger the temperature differential from inside to outside, the higher the rate of transfer. Some people will set their radiators to 6, thinking it gets warmer faster. But instead it just makes it uncomfortable warm inside. I find that setting to 1 or 2 makes the room about 20*c

[@bassplaya69er]

sounds like your flow temperature is too high

[@ConstructiveMinds100]

Sounds like you have not discovered thermostat despite is 21 century

[@regplate2923]

The heating engineer that looks after my system (service and repairs) says his heating is on for 30 mins in the morning. That’s enough, he says. His ‘mrs’ doesn’t agree. I am with her on that one. He’s a cheap-skate.

[@MrPhillipgraham]

Interesting video thanks for sharing. Quite a complicated subject isn't it? It would be great to be able to test solid state heating vs 'on demand heating' say by using one method over a week and the other over another week and comparing total energy used but it's not that simple? Of course external temperature would vary significantly unless you live somewhere where the weather is constant, not the UK! It might be 15c one week and 5c the other! Cheers.

[@beatsg]

Great idea/question

[@4nrgy]

don't even know what to say. COP?? buffer? when temp outside is 10⁰C COP is 3,5 or even 4( this is day) when in nighttime there is 0-2⁰C COP goes down to 2-2,5 . that means it is much more reasonable to heat home during the day and have some kind of a buffer(water tank 200L-500L) to keep this heat through the night. Sorry but this video is just bad

[@HeatGeek]

This is very poor advice. You would need a couple of THOUSAND liter store to heat over night. Night time average in the uk is 7c not 0-2c. It’s drops to an average of 2-7 in December and good installations still perform well over 2.5scop then. Not 2-2.5.

[@denisdolan3679]

excellent, describes my situation to a T! Had a 30 year old boiler changed to a Valliant condensing boiler. Amazed at the difference, but getting a new boiler didnt take into account the 30 year old TRVs. Your explanation of the improvements with heating all the time, (retired in bungalow with solid brick walls) almost decribes me peffectly. thank you. very professionally explained.

[@1evilpie]

Great, informative video. I have a thick floor slab, UFH, ASHP and a home battery. I've recently (last year) found that by running my heating up to 26 over night using my cheap electric (5.5p/kWh about to go up to 8.25p) the heat coming out of the floor slab keeps the house nice and warm up to about 6pm when the heat pump kicks in again to keep it at 20. By doing this I hardly ever need to use any peak rate electric and am saving quite a lot. It seems completely counter-intuitive to have downstairs at its warmest whilst I'm in bed or at work but that's by far the cheapest way to run my house.

[@dhutch2000]

Absolutely not a supprise at all, doesn't always work if you have undersized night storage heaters and only need heat in the evening, but if you have a good size heat store (in this case your floor slab) making use of cheap rate night electricity is a no brainer.

[@ThomasBomb45]

id be curious with regards to flow rate, maintenance, etc how this works out. if the heat pump doesn't suffer efficiency loss or break down, then yes a no brainer. But since those seem to be factors it seems more like a yes brainer

[@KateSilvester]

Hurrah! At last I have found someone explaining and SHOWING how to use the controls on my Air Source Heat Pump. I am pleased I got an AHSP, I just wish the manufacturers instructions were as helpful and as clear as these videos Congratulations Heat Geeks! This is exactly what I have been looking for since I had the system installed.

[@m0aze611]

Thank you for such a thought provoking video and appreciate the time and effort these things take. I’ve passed this on to my two lads who have wet systems as it will help them make a more informed choice than the ones currently doing the rounds. I have a warm air system powered by a very efficient condensing boiler and as we have an open plan ground floor operates very well but I cannot regulate the temperature it operates at but it is much lower than conventional wet systems. As retirees we need heating on all throughout the day and I’ve approached my heating from a similar ‘speeding car’ car approach. The house is quite well insulated, cavity and loft, and my night time stat is set at 16 degrees. Current weather conditions dictate that it does operate, however I build the house temperature slowly first thing in the morning. To help address the cost we go to bed an hour earlier and get up a little later. The first main heat is at 17 degrees for ½ an hour incrementing up to 18 or 18.5 by 10 in the morning. As I have a smart thermostat I can adjust from my armchair raising to 19 degrees early evening. I do supplement the heating when it gets too cold with heated throw-overs which makes us very comfortable. I find that if the house is left to cool down too much you know pretty instantly how hard the boiler works to build up the heat lost - whether all this saves money I can’t say but as you say it’s also about comfort and preserving our health👍🏻 Kindest regards and Merry Christmas Mike

[@briangriffiths114]

In support of your video, my ten year old medium sized 3-bed home (in central Scotland) has the condensing boiler controls permanently set for 15 hours at 19 degrees and 15 degrees overnight which lets the boiler run at peak efficiency. Prior to installing a solar PV system, I consumed only 10,500 units of gas for heating, hot water and cooking but this has further reduced by 2,000 units since I installed a solar PV system with an Eddi energy management unit ensuring surplus generation meets the bulk of the hot water load for nine months of the year.

[@charlespleydell6746]

I've got a Solic immersion diverter on my 1.5kW solar array on my boat and I'd reckon it provides all my hot water for 6 months. They're great aren't they? Only reason it doesn't do more is that I have shading issues for 3 hrs per day. Got to love free heat :-)

[@briangriffiths114]

@@charlespleydell6746 Totally agree!

[@1over137]

40kwh of electric requires about 110kwh of gas be burnt in a CCGT power plant. Fun fact. It's also why you'll find your electric rate is roughly 3 times the gas rate for kwh. Funny that. So unless the entire country starts producing an abundance of renewable power or electric heating is pure evil.

[@richardc1983]

Another excellent video, I do think there are those amongst us though that may still struggle to get it given they may have basic on off systems that go full pelt during the timed period. My parents don't even have a room thermostat. I understand it fully but any chance of a more basic version with less big words lol.

[@HeatGeek]

The subject just is complex. And I'm glad people are starting to realise so, so they will listen to the pros.. hence advising to call a heat geek

[@richardc1983]

@@HeatGeek yep got one going out to my parents tmrw based on your advice for the boiler etc. Please do an even simpler video if possible as I like the car accelerator analogy. Some people will still struggle with the depth. Towards the end even I was seeing double lol but it's late.

[@Wellspicedchaffinch]

Wow you literally just validated that the way I have my Atag i15s boiler setup (for 20 degrees basically all day, and 18.5 degrees at night [because we have a 1 year old who we want to keep warmer than us adults]) is basically optimal. We find the house takes a while to heat up - so running a steady temp all day gives us the comfort levels we want. I have worked from home for 2 years (soon to change) so having a warm house has been helpful/comforting. We have weather comp and its a condensing boiler - and it has low temperatures generally - which is great when you have a little one who you don't want to hurt themselves on a red hot radiator. The new tech in boilers is pretty great - but it's fapping complicated. I reckon 90% of homeowners will never bother to learn about this stuff - and I reckon 70% of plumbers don't understand how to tune a modern heating system. My installer didn't understand how to set it up properly for our home's characteristics, and I don't blame them: you need to live with the home and the heating system - configuring it for 2 to 3 months to get it right. Even after maybe 50 hours tuning everything (TRVs, timings, temps etc) - it still needs a tweak once in a while. It's absolutely exhausting tbh.

[@hunchanchoc8418]

Dec 16th, 2022: My friend's system: A) room thermostats set to 15-17 deg during the day, 10-13 deg overnight (ie NOT warm, just not freezing cold) : Cost £15 per day, £450 a month. B) Thermostats set to 7.5 deg all the time, heating on a timer, for 2 hours in the morning, and 3 hours in the evening: Cost £5 per day, £150 a month. And this is before the energy price caps increase again in April. It is already simply unaffordable.

[@RichardNutman]

Great in-depth video. One thing I don't think you mentioned which might have an impact is the heat-loss rate is also dictated by internal temperature. And this has a big knock on effect. All things being equal, a house at 18 degrees will lose more heat energy in 1 hour, than a house at 16 degrees, due to the increased temperature gradient. This means keeping your house at 18 overnight, instead of setting the set-back temp to like 15, and allowing the house to cool, will result in more heat energy being lost. Once a house drops under 18, it is losing energy at a slower rate. So the warmer house has lost more heat, and therefore will require more energy being put back in.

[@JasperJanssen]

If it’s well insulated enough, the drop in temperature will be so slow that it barely matters. If it’s a drafty shithole like here, it drops 2-3 degrees in an hour or two and it definitely makes a difference. That’s the effect on consumption that’s good when switching temperatures. But if you have to heat it so quickly that your heat source becomes less efficient, or worse yet you have to set the temperature extra high to get it comfortable quickly when you get up, that’s some very negative effects.

[@ich8159]

@@JasperJanssen That is exactly what I experienced. I moved from Germany from a well insulated house with central heating to Ireland into a poorly insulated house with electric heating and all the rules I followed all my life with keeping the heat on at a very low level etc. don’t apply anymore. Once I turn the heating off the room cools down almost immediately and the walls do not hold any heat at all. Turning the heat down or off over night isn’t an option as it takes me half a day to get the temperature back up.. which is bad as I am working from home. I am still not sure what to do. It is easier to maintain 21 Degrees in Germany at an outside temperature of minus 10 Degrees than it is to maintain 17 Degrees in Ireland at an outside temperature of 6 Degrees. I always feel cold here.

[@jimmybrown3380]

@@ich8159 we like to live in Victorian times over here 😂

[@ich8159]

@@jimmybrown3380 You don’t seem to feel the cold. I assume this is the result of conditioning from early childhood on. 😉😂

[@bajatoma]

I am really shocked you have only 38k subs.. man.. every single plumber should subscribe, and every DIY at heart person should.. absolute gold stuff

[@machinehead9334]

Just a thought regarding condensing boilers and a bit on heat pumps for good measure. As you say, the vast majority of people with gas or oil boilers now have condensing boilers. So far, so good. What’s not good is that many, possibly most of these, have been installed and ‘commissioned’ to run at high temperature flow rates, as was the norm on pre-condensing boilers pre 2004/5, and often run at 80* flow and 70* return temperatures (or there or thereabouts). This means that whilst the boilers are indeed ‘condensing boilers’ they rarely, if ever, run in condensing mode. Even this is understandable, given that human nature demands that when cold, you want to warm up as quickly as possible, and people want to practically burn their hands on a stinging hot radiator to prove to themselves that their heating system is on. This video helps to re-educate people on how to effectively and efficiently use their condensing boiler systems. And I believe that re-education is needed, even more so with heat pumps which generally can not operate at these high flow temps. Part (and only part) of the reason why heat pumps have gained a bad reputation for being expensive to run is because people have blasted extra electricity into them in their quest for high temperature heat in short bursts. Liked and subscribed, by the way…

[@kanehardy]

What is the ideal range of flow rate temperatures for a condensing boiler and the optimum operating flow rate temperature within this range?

[@skatergirlskatergirl2486]

So true re education. Just been reading the manual of my brand new Worcester Bosch combi which openly says the boiler has been delivered with the heating settings high. Then buried in the energy consumption table it says that the fabled 98.9% energy efficiency is actually achieved at 30% return temperatures, ie low. But how many people would notice that or even know what a 'low-temperature regime' is? I suppose the manufacturers fear that if they delivered the boiler set at low temperatures, new owners would complain their radiators weren't scorching hot and think the boiler wasn't working.

[@macraghnaill3553]

When I bought this house 28 years ago [built 1970] 3 bed semi] I was told to leave the heating on 24/7 as it's cheaper, I tried various timed settings and it was cheaper to leave it on set at 18c. In 2010 I had a new Baxi Solo 15kw boiler fitted, again tried timed settings I used more gas, timed on 6.30am and off 10pm 3.5 units used, timed on at 4.30am to 10.30pm 2.5 units used , on 24/7 1.5 units used [gas meter is in cubic feet] Unless we have very cold weather usage is pretty much the same Running gas fire and heating I use 2.5 units per day, gas fire on around 12 hours and has an input of 6.85kw output 4kw The best way to see if leaving your heating on 24/7 or timed is to take week when temp and gas usage are the same then try your timed method for 3 days and leaving on 24/7 for 3 days, read your meter before and after each , also turn your boiler temperature setting down to the minimum it will work on, if it numbered 1 to 6 set it to number 1, if it just has an arrow find the best point and mark it . This guy says houses don't normally drop below 16c , mine does, without heating it's about 5c warmer than outside

[@steveh3483]

well explained. My home is quite modern. I increased my loft insulation to 250mm. I installed hive and new radiators, bigger ones and put insulation behind radiators. Set boiler to 60'c By using my heating as normal timed, when I am in, my boiler showed to be on about 3-4 hours on the hive trend graph. By leaving it on at 18 and bumping to 19.5 when I am in, the boiler is on for as little as 35 mins in 24 hrs. I am 100% convinced my fuel usage is so much less. I never used heating like this but its so much better, the whole heat mass of the building and every thing in it, is kept at a constant. I also use stats on all the radiators and a hive thermostat on the rad in the bedroom.

[@richardc1983]

Consider changing the HIVE, the only thing it does that is smart is connect to the internet to turn your heating on and off. It doesn’t;’t allow automatic modulation of the boiler via opentherm (presuming you have a modern boiler).

[@piglet5287]

Buildings rarely fall below 16C? I got up yesterday to find my sitting room temperature was 6.5C. That's in a semi-detached house built 20 years ago with added loft insulation and cavity insulation. During this cold snap in UK, to achieve even a constant 16C indoors I'd need the boiler running all day and night

[@TheGramophoneGirl]

Great video. I've found with my new condensing boiler it uses less if kept running with small drops in internal temp - and a 60c flow temp. If I ran it like an old boiler (2hrs am, off all day, on in eve) then it used loads of gas and the exhaust would boost right out in a big cloud. If I run it continuously it seems to stay in the condensing mode more where it barely uses any gas and the exhaust steam barely 'dribbles' out. I use less gas and the house seems warmer.

[@HA05GER]

Yeh I run mine all the time I believe my flow is at 70 and I very rarely noticed the radiators being hot as the boiler just ticks over instead of flat out then off.

[@JonathanSwiftUK]

Please remember those of us in very old properties, like me, with a ground floor flat, concrete floors, and solid thick walls... but I do have double glazing. Perhaps y ou could cover how this advice can relate to us. What actions could we take to help the boiler.

[@skatergirlskatergirl2486]

I live in an old property like yours, but basement so not even ground floor, concrete floors and thick solid brick walls, single glazed sash windows. I keep every window open a tiny amount (1-2mm) all the time to allow ventilation to prevent condensation and mould. I used to run the boiler twice a day and nearly died of cold in between sessions. Now I run it all day long at about 18deg and it costs about 30% less than before. I haven't run the boiler at night but, having watched this video, now tempted to use a setback temp of 16deg as at this time of year (winter) the flat can drop to 13deg overnight and getting to 18deg from 13 can take about five hours.

[@damienguegan7353]

I have only recently started to look into heat pumps, your videos are so clear and informative, they should be subsidised by the government. Simply amazing!

[@richardlewis5316]

But from the figures given they are expensive to install, ugly radiators and expensive to run if the house is empty until 18.00 every night so it has to be heating an empty house 16 hours a day.

[@ortaparmak]

Here's the proven, by far best way of saving money: leave your heating OFF constantly. Thank me later.

[@exomnius]

You also have to consider that electric prices nowdays in Europe change extremely over the day, sometimes severeal 100 times. For exampel at night the kWh price can be 0,1 cent, but in the afternoon 50 cents, so if you have a Bill that charge per hour it can be alot cheaper to go with the on and off tactics, even if it consume more energy.

[@AllanHundeboll]

Yes fluctuating electric prices is yet another variable that complicates the equation quite a bit

[@filmsbysi]

Thanks for your time, in putting all of these videos together. It's important information for people to have, right now.

[@iap-ug3oy]

Ho! For goodness sake …Push off I don’t need you to tell me what to do……

[@sebscho8027]

Glad I watched this, Just started a bit of a project... 1830's house with Stone staircase, I hadn't considered the Thermal inertia of those stairs or the thick walls. I think the house would benefit from steady state heating - but need to figure out a control set up for the boiler - Where do I start? (no heatGeeks in my area of Montrose, Angus and the 1 in arbroath's website is down.)

[@edinburghheating7414]

Check out Plumbing & Renewables Ltd in Elgin if it's not too late. I met these guys on a training course recently and they know their stuff. They will definitely travel to Montrose.

[@anonimuse6553]

Here in New England, with a large home of over 2k sq. ft. It's best to leave it on steady. It's more comfortable and cost the same or less. You can turn it down at night when everyone is in bed but it doesn't make a lot of difference.

[@drewaitchison3521]

Good info. Here is some more in the form of a filming tip from a professional. It's not a good idea to change camera angles unless you are also changing which camera you are looking into. It's very annoying to the viewer. You are changing angles just because you can and it makes no sense whatsoever and interrupts the flow of your video.

[@johnfoster3286]

There are too many variables from property to property to give a yes no answer. Latitude of the property, windy or not, on the coast, in a velley, loft insulation thickness, wall construction materials and cavity or not, method of heating, zoned or not, timed or not, radiators balanced or not, central heating pipes under the floor insulated or not, age of boiler and fuel that it runs on, window size and orientation, double glazed, etc etc etc.

[@stardust5397]

I live in a 2 bedroom , Victorian, stone built gable end terrace - I have tested this over time in terms of how much my gas bill is and found keeping my several years old Baxi Combi Boiler on 24/7 in winter to maintain an average temp of 20* costs no more than switching it off overnight & off again during the day whilst out at work

[@Thursdaym2]

Interesting but can't understand why you need a temp as high as 20C?

[@zane___k7333]

@@Thursdaym2 why not.

[@nvw2978]

I find 17° temperature positively tropical 🏝. At the moment I’m putting it on for 1 hour a day to take the chill off the air….I set it to 15°, with a hot water bottle I’m toasty

[@bizzielizziearies5439]

It's very true I left mine on 24 hrs to test the theory of a workmate and my gas bill was no higher than when I turned it on and off.

[@Thursdaym2]

@@zane___k7333 Why do you need 20c? Put a sweater on and do some exercise, maybe just walking around the house. Am sorry if you are not physically able to do that. I am 83, my wife is 77 and we have no problem with lower home temperatures.

[@neillewis9888]

Entirely agree. I’ve spent so much time trying to educate friends & family that a consistent, low heat where you just adjust the target temperature during night, day & perhaps evening if you want to comfortably relax is the way to go. When we bought our last house, we had prepayment meters for a while which were obviously awful, but gave me great awareness how much we were spending. Even though I was naive to the flow rate at that point, the constant temperature targets worked a treat. Another level again since I belatedly cottoned on to the flow rate a few years ago…

[@amandadavies..]

I would never ever risk leaving it on. Never did even before all these silly prices. It always went on for an hour twice a day last year and previously....this year it's going on even less.

[@amandadavies..]

@@Borderman47 You're braver than me.

[@HorizonimagingCoUkPhotography]

So so helpful, very well presented! 👏🏻👏🏻🙏🏻

[@chrisardern4594]

So why do other wed sites say the complete opposite. On off on off just once i would like to have a definitive answer.

[@GrahamRead101]

This has to be one of the best videos I’ve seen on this topic. Thank you. I was stuck in the mindset of “on and off” times, despite having a smart thermostat etc. Much food for thought as we have a reasonable thermal mass having internal brick walls, and a condensing boiler etc.

[@HeatGeek]

Thanks Graham. Importantly your smart stat MUST be wired via bus connection. What stat and boiler do you have?

[@RossTallo]

@@HeatGeek Hi there, why is wired controllers critical please? Great channel BTW 👍🏻

[@Felix-st2ue]

​@@RossTalloIf the boilert doesnt know whether the thermostats are open or not it will kick in unnecessary and waste energy.

[@petermartinaitis8166]

I found the less I use my boiler the smaller the fuel bill , pretty obvious really.

[@HeatGeek]

That doesn't mean you couldn't save more necessarily

[@helenleary1327]

Dont put the heating on = £0 ... put the heating on ... and its ££££££'s all the way home!!!!!!

[@almondw]

Your channel deserves way more likes and subscriptions. Liked and subscribed.

[@johntisbury]

Really helpful and well explained. Thank you.

[@Bari_Khan_CEng_CMarEng]

I feel this video has missed the point of passive house design, and the thermal capacity and thermal resistance with reference to the environmental conditions. He mentioned 'inertia' at the end, but that is the actual point of all of this. I feel this video is a dump of just multiple concepts.

[@HeatGeek]

Did you meals the assumption that this video was meant for passive haus?

[@WisdomToAll]

Yes run 24 hours heating and go homeless soon by high energy bill in -7 degree

[@terrymitchell19]

It is quite simple, the heating system replaces the heat lost through the walls, windows and roof. The rate of heat transmission through the walls, windows and roof is directly proportional to the the temperature difference between the inside and outside. If the inside temperature is the same as the outside temperature there will be no heat loss, therefore the lower you can keep the inside temperature the less heat will be lost and less fuel required to replace the heat lost.

[@bobstirling6885]

Not forgetting the insulation levels are the most critical variable in controlling heat loss.

[@Robcomments]

Everything depends on the level of insulation the property have. Cavity insulation on all external walls means all internal walls will heat up with in a few months and help keep the heating off saving gas/money. If you don’t have good insulation costs will be higher regardless of strategy with heating system.

[@harrybrown3657]

6 months later and I believe things have changed. The question for many now is "should I leave the heating turned off permanently" This winter I'm gonna explore a toughening up route. Like first thing in the morning have a hot breakfast and then do a vigorous fitness workout. After a quick shower, dress up with many layers of good clothing. Any time during the day when the house (and I) feels cold I'll do several runs up and down the stairs followed by hot coffee. By around January I'd expect my body to have become adapted to colder conditions. Maybe let up for the Christmas period and have the stat on 16° to give myself a treat. 2022 is feeling worse than 1922..

[@HeatGeek]

I think this video is totally relevant still. Still have it in permanent where is suits as described, but what target temperature should I turn down to. The and answer is one you can afford

[@harrybrown3657]

@@HeatGeek Absolutely! Your channel is very relevant. My comment is related to our local energy prices having doubled since last year and therefore I dread the coming Winter. And yes, I'm on low income so I'll have to brave it out like many others ☺

[@helenalovelock1030]

😂😂😂😂

[@PaulStephenson-zm8gy]

I have long espoused and operated this method. I have a programmable thermostat so I simply set the temperature for different times of the day and leave the heating on round the clock. It costs no more to keep the house relatively warm by heating constantly as opposed to letting the fabric (thermal mass) go cold and then burning loads of gas to get it back up to the desired temperature.

[@1over137]

"It's rare that a house will get below 16*C over night" You clearly live in a NEW building built in this century. You come live in my 1960s house that was coal fired when built and has more ventilation than insulation! Seriously. It has 6 air bricks below the floor level. You can see on the thermal camera it has air leaks everywhere. Lots of deep blue cold lines in all the corners of exterior walls. Most of the double glazing is now 40 years old, the voids have gone and they all have air leaks at the seals. All of this is "fixable", but it's extremely expensive and as I found out, has to be done carefully. I got my loft insulated and vented. Great! WRONG! Cheap contractors went ahead and did it, but did not check the building design first. Venting the roof did nothing but turn the whole house into a chimney. Warm air from downstairs rises, passes out the air gap at the top of the old airing cupboard for the hot tank, into the attic and out the vents. Worse still, the bedroom sits in a dormer. It does not have any insulation between the bedroom walls and the attic. The space you need to get to to fix that is inaccessible without cutting into walls and ceilings. It's a right mess. I've expanding foamed most of the air gaps to the attic, but the hallway will easily get down to 9*C in winter if the heating is off. Yes, that is indoors. The bedroom itself, can sustain a maximum temperature delta to outside of about 20*C. The radiator can't keep up with more. So when it's -5*C outside, it's 15*C in my bedroom! Luckily I like it cold. To do it right, I need to consult an actual builder on insulating house properly, with consideration of it's wide open, highly vented, 100kW open coal fire heating design. In coal fired buildings they tend to literally "fire the brick work" and literally heat the building up. As fires are usually (re)lit in morning and deadened down for bed, they produce heat 24/7 and the brick work stays warm and transfers heat through the building. All but 1 room has a bit of chimney breast in it. That is all by design. Use the chimney brick work to heat the house. So, to modernise that and insulate it properly will be a big job. The air brick vents need re-considered. Downstairs flooring needs lifted and vapour barrier insulation installed under the carpets/tiles. The air gaps need to be sealed. The glazing needs replaced. The "facia" needs drilled/vented to stop the attic pulling air out of the house when convecting. The bedroom inner wall needs to be reached and lined with insulation. The hallway stairs ceiling needs taken down and insulated (it has bare vented roof above). About half the radiators need replaced or upgraded to doubles. We are looking at £5000 for the insulation upgrades + about £7000 to reglaze the place. It will retain value in the house and may increase it if I can lift it's official energy rating of "F+" to a D maybe.

[@HeatGeek]

Yes rare. Most victorian and Edwardian houses now have double galsing and loft insulation.

[@HeatGeek]

Saying that you live in one of the rare houses does not make them more popular

[@1over137]

@@HeatGeek I'd say 90% of the housing stock in my town was built in the 1970s and earlier. It was ALL coal fired, then town (coal) gas fired including a back boiler. Then that was ripped out and oil fired put in (late 80s) and double glazing installed. I upgraded to a condensing combi, insulated the attic, but I still have a long way to go. Glazing is next, but I need to sort the dormer insulation and have someone address air gaps. I speak with friends, family who live in similar and older houses and invariably the hide in one room in winter and let the house go cold as it can't be heated. I've lived in an appartment built in 2004. The heating wasn't needed from April until November and run time only exceeded about 2 hours a day in January! In this 1960s house, I'm struggling to keep 65*C run times below 6 hours. (although I realise the periles of using runtime for calculations with a modulating boiler).

[@1over137]

@@HeatGeek The last victorian era house I lived in had a 1cm gap under the front door and iron skylights which dripped on you in winter and balanced pull up/down sliding windows. It was also a fortune to heat.

[@1over137]

I'm kinda getting a vibe here, basically I'm going guess your services are quiet expensive. Properly excellent quality, but expensive. Thus, you are mostly going to be dealing with people who can actually afford to spend money addressing their heating efficency. The people who don't come to you as a customer are the ones who can't afford to use your services and they are the people most likely to be living in the older, poorly insulated, unmodernised 50-200 year old buildings in poverty.

[@shaunbromley8445]

16° overnight! My house drops down to 10° overnight with no heat on!

[@chrisbw591]

Great video - as a gas Engineer with poor training it’s beneficial 👍🏻

[@Lee.Willcox]

Nine months later with the energy hike, I have noticed this. I leave two oil filled electric radiators on all day and night. I keep rooms we don't used closed. During the night they cost £1.30 and during the day the are costing £4.20. The rooms we use, Kitchen, Living Room, Bathroom and Bedroom are all toasty. Since doing this we are now over £1000.00 in credit with our energy supplier Octopus and I can prove this if you question me. We are asking for the money back as we now have our home regulated properly. Two electric Oil Rads on 24/7 and we are toasty. Both are set to 21c.. Where does the £1000.00+ credit come from? £305.00 a month for over a year when we spend on average over the summer and winter £4.00 a day. £305.00 a month is equiv to a budget of £10.00 a day. Some days We don't even reach £1.00.

[@waynegazard5038]

Thanks for a educated unbiased explanation. I've been into heating since 60s dip67 didn't even need electrics, gravity heating /hotwater clockwork 7 day timer ,more a electronics engineer than gas fitter at retirement. From over engineered vailliants to camping quality French/Italian appliances, rule of thumb as you said bigger hse bigger the bill. Personally pushing heatpumps like diesel cars now electric government wrong.

[@Queendoobie]

This video has helped so much I am in a housing association 1920s large roomed through terrace high ceilings large rooms and my heating bills were beyond high I am not well and home a lot and totally clueless about managing my boiler n thermostat my home was either too hot or too cold I had no idea about how to manage the hand I have a lovely housing association but never informed of anything regarding this and especially with the cost of living and rising fuel prices,I truly believe we need more information out there for pp on low income but I till I decided to google how to manage my ideal boiler n thermostat because the bills n the too hot too cold home so thank you I am going to rewatch again 🙏🏻🔥🥶

[@henryshannon2013]

Very informative, I have been telling friends the same story for years but I don't think that many believe me. Well done!

[@andymerrett]

"It's not often that a building will drop below 16C overnight". LOL really?

[@robertlamont9455]

Very good indeed, but a few observations Background - My own home is a modern double glazed insulated two storey of 100m2, high thermal mass with plastered walls downstairs, low thermal mass upstairs - Having a monitoring system which tracks temps, gas, etc., I was able to tinker and observe the response. The Buderus gas combi runs 24/7, but actual feed temperature versus displayed was adrift -5 to -10 degrees (non-linear). Main thermostat is set at 19.5. As installed, the pump was running full blast, I reduced it to the middle setting once I'd figured what the total required flow was (uses less power to no detriment), and time to boiler temperature was faster. All but the main radiators were found oversized ca 40%, the main rads were changed from -9% to +9%, constant flow type thermostatic valves (minus the thermostat head for the mains) were subsequently fitted throughout so system balance is constant. Were it physically possible I'd bump the mains to +40%, the why will become clearer. Winter temps here can fall to -20 so after adding additional insulation and playing with the system for 5 years to very good effect, some observations on setback and boiler temps for homes of high thermal mass. Figure out your boiler cycle time, viz when the return temp ramps up, the boiler is more efficient the cooler the return, it is important. Don't take the displayed temp as gospel, check it, and don't be concerned by the output temperature, it's the return which derives efficiency. If reducing temps, check the cycle time when returning to normal, it is more efficient to step it up gradually, even if it takes two cycles. eg I know my main rads begin pushing heat back to the combi ca 18 minutes into a heat cycle - If it goes over 21 minutes I bump the boiler temp by 5c to bring the cycle back down, getting so far as 70c (in reality 60) in the last winter (-15) with considerably less gas consumed than having longer cycles. If going away and coming back to a cold house, take it up in small bites (in my case 20 min cycles) leaving it for a half hour. I made the same 2 week winter trip in two consecutive years, leaving the house set to 10c - First year I let it run for hours, second year took it up in stages, same time to target temperature but saved massively on gas consumed after the second trip. :) Bumping insulation levels made by far the greatest impact, lopping 50% off my gas consumption immediately, it's been dropping slowly ever since which has been a bonus. I'd have loved to have fitted an opentherm board to the boiler, but it was so expensive and locked in protocols I gave up on the idea. Good luck.

[@bhut1571]

There are many variables including the evening cost for electricity. The main point is that hot objects lose heat energy faster than cool ones so simple thinking is cool is good. Here in N. Ontario I keep the night-time temp set at 15.5 C, day at 18 C and evening at 18.5 C. Our former inefficient gas furnace (air ducts) was still running well after 45 years of use. Our present gas-condensing furnace has functioned well for 15 years despite the morning chug. The true test is to experiment with different homes and heating systems comparing energy cost and equipment costs over the long haul.

[@terryfinch9319]

Brilliant even for heating engineers 👍

[@GoldenMarky]

This video is a money grab, no point watching

[@HeatGeek]

Keen to know in which way this makes us money?

[@DIYJase]

Fantastic info, just come across your channel. Unfortunately we have a house that has electric underfloor heating throught the entire house. Qe since a boiler for hot water and towel radiators. Any advice on best way to be energy efficient with whole house electric UFH? Thanks for your videos Jase

[@PaulBrunt]

This seems quite complicated for people. Why don't heat pump simply have a PID control systems? Surely nowadays it would be relatively straight forward, and I would imagine superior from a users perspective as the system can adjust to the current situation much faster then tweaking static curves. Seems like such a system would be able to infer the current heat loss of the house dynamically based on the internal thermostat without the need for weather compensation. It works well for 3d printers, which perfectly maintain temperatures by modulating the energy input.

[@BarryFlo58]

We live in a 4 bedroom semi and our heating is on 21 degrees, 24/7, 365 days of the year and our energy bills never raise with rebates every year. Our central heating is by a gas boiler, our loft is insulated as are our walls.

[@thread_astaire]

Also, I’d be interested to hear your views on infrared heating panels. With my home being new and very well insulated, I’d like to get off gas. I want to install solar and a 12kw battery. I’m not sold on ASHP because my radiators are all on microbore, so I just don’t see how I’m going to get a decent flow temperature. Soon, time of use tariffs will revolutionise energy prices for those who have Battery solar. There will be times of day when electricity has a negative cost point and your battery will charge not only for free, they will pay you to charge it. That not even including charging from the solar and running your house on solar. Such tariffs will make infrared less cost prohibitive when it comes to consumption.

[@lafamillecarrington]

Brilliant, thanks. I am retired and have recently installed an air-source heat pump, which we run at a higher temperature during the day. It has made our lives so much more comfortable. Now we plan to make the house (1900, solid-walled, detached) as energy efficient as possible - so I will be watching more of your videos. Sadly your map shows that Cambridge is not a place where Heat Geeks are active!

[@HeatGeek]

Bit of a black hole around there at the moment!

[@JohnBell-rf6oj]

@@HeatGeek Also North Wales!

[@richsmart321]

Absolutely no clue now! Too many variables - if only there was a website that took all these in to account and gave you best advice

[@1over137]

I use schedules, sensors and presence indicators (is the TV on in the room?) to change target temps. Different rooms have different targets at different times of the day. Last time I intervened and touched the heating was April to turn the flow temp down to 45*C for summer. Before that it was months and that was a reboot to add a new feature to the system. Normally, when I'm out all day at work, I have a morning and an evening schedule which sets those "setback temps" as you call them, to "medium", a few degrees cooler than "comfortable". Outside of those times the setback temps down another few degrees, ending up around 16*C when the house is vacant, idle or overnight. If a room is in use (TV on), the temp goes to "comfort" level in that room, say 20*C for the office, 19*C for the living room, 18*C for the bedroom. The rest of the house is "unzoned" but has TRVs set to 2 or 3 and 5 in the bathroom. The balance I am running is with the thermal mass, I'm not really heating up the brick/block work, so I'm just getting air temp up and when the heating goes back off, the brickwork quickly absorbs that heat. Given my heat loss issues explain in another comment, I'm kinda stuck this way for now. An idea did cross my mind to more directly heat the brick work, just like a coal fire would have. Not quite sure the cheapest way to achieve that. Blasting the heating won't do it, the building loses too much too fast over 20*C. Direct heat is dangerous as it's got wall paper. Anyway with prices as they are this autumn. I'm setting my minimum temps down to 14*C and setting up humidity monitoring, heating to lower RH in "emergencies" and weather compensation to try and avoid damp due to ambient temp/pressure changes. At 14*C you are right on the damp line so humidity becomes very important.

[@TheZippyMark]

How are you achieving all that out of interest? Smart TRVs?

[@wobnoway5692]

Firstly, don't stop doing these videos it really brings these important points to people's attention, any comments of mine is subject to discussion ;-). I had one comment to add/make, when intermittent heating with a lower delta t you will have a lower heat loss, I'm thinking can i be bothered to calculate this for my own home. Anyway many years ago i just used to give advice on heating as you put it about occupancy e.g. if your home a lot then underfloor is brilliant, if your at work all day and out on weekends then radiators or fan coils (love fan coil). A test was carried out with heat pumps in same house types, one ran at a constant 21 the other time clocked for 6 hours of the day. The one on all the time had a great SCOP compared to the other, but the other was less money to run a year (£200, at the time). Anyway all the best.

[@pawelnotts]

I miss the time when I was living in a 70s flat in Poland heated up by the hot water from a nearby power plant (whole city runs on this). Radiators would come on in autumn and go off in the spring, steady temperature throughout the day with lower temps during the night (you can obviously dial down the rads yourself if you want). No mold, nice and toasty 23C all the time and none of the faff I'm having now in a detached house 😂

[@thread_astaire]

This is a really interesting thread. I’ve a new home and it’s insulated to death. I have dual zone thermostats. My heating doesn’t seem to come on below 22.5. Why is this? Do I just need to get upgraded thermostats to fix this?

[@peterborthwick1247]

Excellent stuff. Really clear and well explained. Why don't more people just tell it like it is, calmly, without sensationalism and trying to sell us something!! BUT, What no search facility on the website? (thought I'd look up more about weather compensation versus room controls..)

[@HeatGeek]

thankyou! There's a search butting top right! www.heatgeek.com/?s=weather+compensation

[@Space-O-2001]

Great video - looks like you've taken editing tips from mrwhosetheboss :P

[@VideofoundryNet]

"So even if you do use a fraction more fuel by running all day the small ammount of extra fuel may be worth the increased comfort and lower maintenance costs" - I would like to query this. Newton's law of cooling, that the rate of heat transfer is proportional to the temperature difference, means that the HP has less work to do to raise the temperature from external temperature to setback temperature, than to keep the house at setback temperature all day. And I would think that less work would mean lower maintenance costs. The return fluid to the HP may be colder for a time than in the steady-state case, but why would this damage the heat pump? And it won't increase comfort because I normally throw the windows open when I get up so any heating by the HP will be wasted. I have a 1980's boiler which is being replaced by an ASHP. I only use the boiler from 6pm to midnight, with the thermostat on 14 C. Watching these videos I am becoming increasingly concerned about the changes I will have to make to life. Switching the HP on at 3 pm, because the low operating temperature means it is slow to heat up - OK, keeping the windows closed permanently - no way.

[@WhatDadIsUpTo]

Take a queue from Mother Nature. Ground temperature 2 meters below ground level remains constant year round, varying only by a swing of about 5°. That said, my next house will be covered with dirt, with a central patio open to sky. I plan on heating the floors using hydronics.

[@richardlewis5316]

I have just established that a heat pump consumes about 2kw per hour. If run 24/7 this consume 48kwh which at my current EDF rate of 37p/kw will cost about £17 PER DAY to run. How can this be a viable alternative to gas even if running only 16 hours a day.

[@richardlewis5316]

@@DarthW909 From all the figures shown by Heat Geek I have assumed that the HP will be running at about 2.0kw per hour. OK it may be half that but never less than 1kw so if running 24/7 this will be about £9.00 PER DAY or £270 per month. Heating a house 24/7 is so unnecessary if a gas boiler can heat it in 2 hours

[@lumsdot]

I like the car journey example, but a lot of people are out at work, so if using non heat pump, just turn it off, my house takes about 30 minutes to heat up when I get home, and gets turned fully off when I go to bed, and have an electric oil heater in my bedroom if it gets really cold at night

[@pumpkinhead456]

My house takes 6 hours to heat up unless the boiler is working hard, and therefore less efficiently. Horses for courses#

[@richardlewis5316]

My lifestyle is similar. I don't put the heat on at all in the morning - get up, get dressed, breakfast and away!! At night I come home and if I'm staying in I put the gas boiler on for an hour or two. House get comfortable and if by mid evening I'm getting cold I put a jumper on and in bed an electric blanket!!

[@goingwildagain]

Temp often dosent drop below 18 at night you are joking. Ive insulated walls roof yet my house without heating when outside temp if 5 Deg c leaves my house inside around 10 Deg C inside so heating needed. I ok with cool so i find my home warm at 16 Deg C.

[@starsailor49]

We installed a Heat Pump system in our home, Suffolk, England a few years ago. We insulated EVERYTHING, ceilings, walls, floors and windows. We tried running the system all day at 18C. This resulted in a one day KWh and standing charge if over £18.00p (£548.00 per month). Leaving your heat pump running all day will result in crippling bills!

[@Keano20]

Agree! I am having the same issue in North America! What is the solution? Setback or not? Or go back to gas furnace?

[@Sworn973]

So, one can assume that those new smart inverter AC unit with hot/cold, can be just ON all the time, as they do the switching for you, or would it still be better to just manually schedule turning it on / off. Of course I know that depends on branding and other crap, but just as a general idea based on common smart inverter used now a day.

[@oheadmusic]

I never meet people in real life who constantly wave their arms around when talking

[@HeatGeek]

Sorry to hear that

[@timtam6442]

In autumn and winter my heat pump is on 24/7 at 22 degs. We have intelligent Octopus Go and pay pennies on the small hours so it’s not worth turning off, especially with 3 women living in the house! I used to spend a fortune on heating oil in return for a cold house. I now spend the same but have a lovely warm house all day and all night.

[@howardskeivys4184]

So, I have a 21 feet long, 17 feet wide, 7.5 feet high, well insulated lounge. I have the thermostat set to 21c. I have a 3kw electric radiator which I use to heat that lounge. The radiator is equipped with 3 power options. 1kw, 2kw and 3kw. If I select the 1kw option, it will raise the temperature to 21C, but take a long time to achieve that. It will maintain that temperature, vut will be running pretty much constantly. If I select the 3kw option, it will heat the room quickly, and maintain that temperature by switching on and off as appropriate. The 2kw option, falls somewhere in the middle. Which option would prove most cost effective?

[@stevecraft00]

I fitted an eph controller with opentherm. The rooms are far more comfortable and the boiler runs quieter. Fairly sure it is using less fuel, but i still set the setback to a low level, about 14 degrees. I programmed every day for the times we are in, we have a fairly consistent routine. When the program temperature rises the boiler fires fairly high but soon drops down within half an hour, with the radiators only being warm. But it isnt going on at all until october, or the internal temp drops to 17 deg. 😂

[@cc-iq2bs]

No i leave mine turned off , and I do actually pay much much less. Its not our fault yoy the industry invent products and add on products and insulation . I'm not leaving heating on all the time, that's just dumb, and I did it my way, hee hee boom Yes I do pay less , way less . There is no need at all to leave a heater on all day , that's silly I don't even have heating on at night . I got sick and tired of paying big bills and I'm not doing it anymore , simple as that I'm not So I turned it off and kept it off , and my bills dropped big time , I'm sick of throwing money away to these companies , so I took matters into my own hands . Mine is off I would say for Jan to November ish. Yes I'm serious , I boil water in kettle for sink , works just fine . So my wages and money is staying in my bank, not leaving my bank, and I'm saving a hell of a lot money . I bet most are spaying crazy bills , NOT ME I'm not following like sheep ,

[@colinsutcliffe768]

It is complicated 😕

[@TheSpoovy]

This is a great channel I'm learning a lot.

[@blueberry-gy7on]

why is there music playing while he is speaking. i've got to strain to hear what he is saying.

[@jakeblair4215]

For those with electric radiators, get octopus agile tarriff for 75% reduction on peak rates during the night ri warm the house. Bonus okints for investing 2-3k for battery storage to dissipate stored energy during peak times. Payback period is 3 years. (Note youndont have to buy a teska £9k battery)

[@helenalovelock1030]

HOT WATER Do you know about immersion hot water with a tank that insulated well ? Best to leave on or switch on and off when needed. We have solar every in the day time so thinking maybe best to leave on ?

[@RogerHolden]

Great video. We have a 30's house, but refurbished and generally very well insulated and double glazed. We have a condensing gas boiler and the house heats up very quickly. I was interested though in your comment about the overnight temperature generally not dropping below 16. We live on the south coast (Sussex), so it's quite mild, and we're often down to 14 -15 overnight in winter. What should I look for first for heat loss? Loft is insulated so not sure where we're losing it...

[@smrtysam]

I think Roger and Vicky know each other.

[@BillsCountrysideAdventures]

This was bit of misleading, I don't see this anything to do with heat pumps. I might be wrong but feel it was more about gas boilers.

[@HeatGeek]

It's relevant for both condensing gas boilers and heat pumps..

[@BillsCountrysideAdventures]

@@HeatGeek it takes a long time for heat pumps to stop and start, or am I wrong?

[@HeatGeek]

@@BillsCountrysideAdventures I suppose what you think a long time is. A boiler takes about 3 seconds. A heat pump is about a minute so I suppose so.

[@gregorygreg4263]

I've been heating with a combi boiler and radiator for years. I just changed and it was the same again please. I looked at the heat pumps and it was costly and more than I could afford. Even with the grants. We have a twelve year parts and labour guarantee as long as the boiler is serviced once a year. This is registered with Bosh. This new boiler cost 3000 pounds installed. I would like to see that done with a heat pump system. We heat all year round it goes to 17c at night but really falls below 18 degrees c turns on at 5am and stays on until 10pm at 19degrees all day. Cheap as chips costs around 3:00 a day in winter. Occupancy someone at home all day.

[@helenleary1327]

We run our home at 13 deg ...day in .. day out !!! We heat ourselves from within ... and use thermal throws in betweenn.. heat from within ...

[@parsonk4041]

That still sounds quite cold.

[@amandadavies..]

@@parsonk4041 15 /16 is very cold to me, and ours is that most of the time. Too bad though....I agree with Helen. Way too expensive....even before all the current madness.

[@marlls1989]

18 is my comfort temperature during the day and during the night I might even turn it off completely or leave at 15 just in case for when waking up. Anything above 20 is too hot to be comfortable

[@paulgoffin8054]

Not understanding "set back". We currently have gas. We don't want our home to be over 15C in the bedrooms overnight. How does setting back the demand change the efficiency when the set back is removed - when the set point is restored to "daytime" operation? Won't the HP see the home as way below temperature and heat up in an inefficient way? Are the controllers intelligent enough to work out "no rush, take it steady"? Otherwise it seems we'd need to have the bedroom windows wide open in winter which can't be good.

[@michaelpalfreman9923]

What about the droning of the pump during the night especially where the boiler/pump is located in a cupboard near the bedroom I just could not sleep through it Constant heat surely causes dry atmospheres and stale air And some flues can be noisy which is more noticeable at night. It seems in the fiture we will have humming heat pumps to contend with. City dwellersayvsay so what but we currently live in a quiet area.

[@purge98]

Why are there so many variables for heat pumps BUT few for a gas boiler? I don't want massive radiators replacing my existing ones and where will the new tank go? I'll stay with gas thanks.