Vaillant Heat Pump and Mixergy tank installation experiences - Dorset, UK

The video discusses the experience of having an ancient gas boiler replaced by a Vaillant AroTherm Split 7kW heat pump and and Mixergy hot water cyclinder. The installation included an Open Energy Monitor heat pump monitor, and this is shown too. The successful and professional job was carried out by InaFix, a small company based in Shaftesbury.

[@Ben-gm9lo]

What a lovely couple. Thanks so much for having the courage and energy to document your journey and share it with us. We are waiting for Custom Renewables to fit our 7kW Vaillant based system, so it was good value to watch your experience. We initially tried Octopus in 2023, but they are trying to promote economic solutions to help mass adoption, so their product doesn't flex well to individual requirements. We want to fit our external unit above a flat roof and they only install at ground level. We tried BT too, but their beaurocracy defeated that attempt too. We ended up going through Heat Geek, not cheap, but definitely promising for a quality product. Time will tell.

[@jeffjsmith]

Thanks for your kind comments. I am sure that you will get an excellent job from Heat Geek. The installer choice is even more important than the heat pump choice!

[@dorsetengineering]

Nice to see another Dorset resident posting their heat pump journey on KZbin. I’m also in Purbeck.

[@jeffjsmith]

It is proving to be a good journey so far here. Thanks!

[@willj1927]

Fortunately our forefathers had the foresight to build you a plant room for all the kit!

[@jeffjsmith]

Yes, it used to be the outside loo - just big enough for the equipment.

[@peterthefoxx]

Great video. The Daikin heat pump is a little noisier than I’d like so this seems like a great choice. It’s not ‘noisy’ but I there is a noticeable background hum when it’s running.

[@jeffjsmith]

Yes - it was the upside of the planning delays!

[@jeanh9641]

Well done for your perseverance.

[@jeffjsmith]

Yes, we did wonder sometimes ... But it was worth it certainly.

[@robertriebli1263]

Thank you for the good Info!

[@jeffjsmith]

Thanks for the comment!

[@derekpaisley620]

Good video, installation looks good. Only the heat pump base looks a bit suspect. Keep an eye on the unit keeping level. Thanks for the upload.

[@jeffjsmith]

The heat pump is bolted onto those rubberised feet and seems pretty stable. The ground underneath seems very stable, so I'm hopeful, but it is a good idea to keep an eye on it for a continued level placement. Thanks!

[@angiej4865]

Thanks for posting. I'm on the ASHP journey too, in my Purbeck area renovation. I'd have been interested to know the final cost of the installation.

[@jeffjsmith]

Hi, it was affordable with the Boiler Upgrade Scheme help. Probably not as cheap as a replacement gas boiler would have been, but it allows us to stop using gas, removes the gas standing charge, and make great sense by having solar panels and a battery too. I would contact Octopus and a couple of local installers - especially those who have been recommended personally. I hope you can move forward with a local installer. Best regards, Jeff

[@philreilly6959]

I enjoyed watching your video. I'm just waiting for Octopus to produce a design for our system. Fingers crossed that we don't have the problems that you had. However, Ecobubl certainly found you a really great install team. It looks like an excellent installation. Your outside storage cupboard was ideal as a plant room, wasn't it! (On a different subject entirely, I noticed that you have a piece of guttering catching rainwater from the storage cupboard. Have you thought of extending the gutter on the left hand side at a right angle until it's above the garden and putting the downpipe there instead of its current position? That way it would be out of the way! Just a thought.)

[@jeffjsmith]

Thanks for the comments. You are right, the guttering in the video was a temporary arrangement. It now runs to the existing downpipes from the roof by being extended above the heat pump. We had to wait until the gas boiler had been removed to be able to do that part. All good fun!

[@adamsweet3587]

I'm building a passive house in Cornwall That will ultimately use a Vaillant heat pump. I have just finished the heat geek course Mastery, and wondered if an accurate heat loss survey has been done before sizing the heat pump and if you have zoning, i.e. thermostats in rooms. The general thinking now to minimise cycling, is now to have no zones and to balance out your house using the weather compensation facility. This will reduce the system flow temperatures and improve COP (efficiency). Regards Adam

[@jeffjsmith]

There was a heat loss survey done, whether it was accurate is hard to say. The upstairs bedrooms have angled ceilings which are pretty close to the roof, and I'm not convinced they were accounted for in detail. We have the Vaillant indoor display with the temperature gauge on it, and an OEM thermostat for reference in the lounge. The heat pump id set to weather compensation and it seems to do a good job for us, as well as seeming to be efficient. We do have TRV's on the radiators to give some adjustment if needed.

[@jchidley]

7kW does seems large for your property but you are getting good performance. Clearly cycling isn't a problem. It must be a well installed good design.

[@jeffjsmith]

Yes, it might be larger than absolutely required, but it does seem to run efficiently.

[@normanboyes4983]

Thank you for taking the time to document your installation. A very good move to install the monitoring equipment. Are you running this system using weather compensation or fixed flow temperature?

[@jeffjsmith]

Thanks for the comment. Yes, we are running with pure weather compensation set on the heat pump.

[@UFZ7482]

Thanks for posting,... you refer to it as a split system, but it looks more like a standard arotherm plus with a hydraulic station?

[@jeffjsmith]

It is split, with the heat extraction being done by the outdoor unit, the refrigerant carrying the heat to the indoor unit, and the heat being exchanged there to the water - for the radiator circuit or the hot water cylinder. It is a more complex install, but it got round the issue we had with the R290 refrigerant since it uses R410a instead. Not so environmentally friendly, but it is unlikely to have a leak I hope.

[@UFZ7482]

@@jeffjsmith Thanks for the reply, ah yes when i looked again i see the difference.

[@speedbird300]

Isn’t that closer to window tham installation guide?

[@jeffjsmith]

The issue with proximity to windows was the problem using the standard mono block Arotherm Plus which uses R290 refrigerant - propane. This led us to use the AroTherm Split which uses R410A which doesn't have the installation constraints.

[@pmbpmb5416]

Bureaucracy ! A couple of decibels , you could understand in your case with neighbours so close if it were a little higher perhaps , but a couple , this is the contradiction, you are implored to do this and then big government gets in the way , although for some regs I believe they are changing .

[@jeffjsmith]

Yes, it did seem crazy that we are being encouraged on one side to help in reaching net zero, and on the other hand public health is inflexible. I do believe that this will be sorted out soon, I certainly hope so. The saving grace was that due to the delay we got a bigger boiler upgrade scheme grant!

[@bordersw1239]

Decibels are not linear.

[@pmbpmb5416]

Ok , so the point really is if it were that close why apply the rule so rigidly ? You surely get the point in the current environment using what borders on petty bureaucracy to put obstacles in the way of someone trying to do as requested , it’s pencil necks gone mad .

[@ciaranclose192]

This seems very strange that planning were such a big obstruction to you just fitting a monoblock unit... if i were you i would make a big deal of this considering we are trying to promote heat pumps.. terrible... you cant even hear a monoblock unit!

[@jeffjsmith]

We did make a reasonably push against the Planning people - but our life is too short and we actually ended up with a better solution I think. But the process does need sorting out.

[@markchristohperowen6806]

the problem came from installation guys at the start(years ago) installing them too close to neighbours windows in old small 1 bedroom quarry mens cottages etc. the units were LOUD. lines were drawn and DB levels need to be followed. its great having an environmentally friendly holiday/permanent home but not at neighbours expense. lovely couple glad they persisted and worked around it. btw personally i agree with you very doubtful in that instance it would have caused a problem, maybe it was too close to that bedroom window? people should be allowed to leave their windows open and have a good nights sleep during warm weather. fans and internals dont sound like they used to, octopus should go back to dakin and make their heatpump designers aware so they can bring their units inline.

[@Alsmithize]

Planning department are a bunch of vultures

[@jeffjsmith]

It did feel like that at times!

[@matthart5215]

@UrbanPlumbers