Why did you choose an air source heat pump?

[SimonD]

There always lots of content about why not to get a heat pump installed, but I would like to know why you chose to get a heat pump installed instead of a fossil fuel boiler? Doesn't matter whether it's for retrofit/renovation or new build, I'm just interested to know. And what were the pain points that were most difficult to overcome? Was it just the price or is it in line with so many posts on BH that it's difficult to find a decent system designer and installer?

[JohnMo]

26 minutes ago, SimonD said:

why you chose to get a heat pump

Swopped from gas in stages, but ASHP motivation was cooling via UFH.

 

The boiler basically ended having to go it couldn't pay it's way, with gas standing charges and preferentially better ToU tariffs for electric, once I got the smart meter sorted

[ProDave]

I was building a new house that I knew would be well insulated, airtight and low energy.  There is no mains gas here, so other realistic choices were oil boiler or lpg gas boiler.  I did not want an outside tank taking up space and looking ugly.

 

So i chose ASHP.  Entirely self installed with UFH.  Cost of parts no more than oil boiler and oil tank and not difficult.  ASHP gives electric heating at comperable running cost to fossil fuel boiler, so what is not to like.

[Nestor]

No mains gas and used oil in the past.

New self build, air tight, MVHR, 3G etc. 275sqm.

RHI was available so paid for kit and install.

Our personal use for 2025 was 2700kWh for hot water and heating.

However, I would not recommend ASHP in average insulated home with mains gas available if cost is a major factor.

[Dreadnaught]

New build. Had gas available.

 

Chose ASHP because (i) fuel bills are lower; (ii) low-and-steady gives a nicer sense of warmth; (ii) cooling in summer; and (iii) and especially because it gives a whisper quiet home as the main noise-generating part is located outside.

[Andeh]

Was a tricky decision, as I knew nothing about them and have always had gas in the past. I love my technology, but worried about earlier adopting, and shortage of skilled people on them. Had gas available and on site already.. So seemed mad not too just keep it simple. Even with UFH and the Grant... I still wasn't sure. 

 

Architect and builder both looked at me as if I was mad when I hesitated over ASHP, and explained the above.... I generally declined but said I'd think about it. The builder went ahead and costed and put it into the plans anyway. 

 oooooooh were they correct.

 

I love the ASHP, it works well, is cheaper then gas, with smart tariffs it's just brilliant. No gas standing charge , no big noisy boiler inside the house, no stupidly high flow temp to then try and reduce for the UFH. 

[JohnMo]

12 minutes ago, Andeh said:

no big noisy boiler inside the house, no stupidly high flow temp to then try and reduce for the UFH

If you get that it's just piss poor design from installer not the boiler. Mine was pretty much silent, directly connected to UFH manifold no mixer and pump. Just ran a steady 32 degs, and was managed by a low hysterisis thermostat. When it did DHW it just ramped up slowly to 60 degs, by the time it got the cylinder was at 52 degs.

[Beau]

We moved into my late parents old place that had no central heating and just an LPG AGA and wood burners (no mains gas available). The AGA was using over 2k of bulk LPG a year and only heated a couple of rooms, hot water and cooking. Having had a heat pump in the form of a GSHP for 18 years in our previous barn we were comfortable a well designed heat pump system would work well enough. We didn't cost up a FF heating system and just went straight for the heat pump as we could afford it, it shouldn't be more expensive to run and has environmental benefits. A year in its managed an SCOP of over 4 and cost around £850 a year to run. The heat pump grant combined with getting the VAT back on all the radiator work made this all a lot less painful than it might have been.

 

Edit. We went for air source over ground source as I couldn't face the chaotic mess of the trenches for a GSHP which would have to go through our yard which is our main farm access and has lots of drains and water supplies in it. 

Edited yesterday at 09:11 by Beau

[Post and beam]

New build well insulated, UFH and air tight ( ish). 

Mains gas is not available on our plot and the delivery was going to be £6500. Not usually factored in when people discuss how expensive heat pumps are.

Finding a heat pump installer was difficult and to be honest the company i chose have ended up being a total incompetent nightmare. Hey ho! lesson learned.

 

[DamonHD]

Because our gas boiler kept expensively failing so replacing it is expected to be a financial win, and I am definitely a supporter of electrifying everything, and heat pumps are the main focus of my PhD research!

 

Part of my reasoning is here: https://www.earth.org.uk/note-on-combi-replacement-dilemma.html

Edited yesterday at 10:06 by DamonHD

[sharpener]

190 sq m  barn conversion dating from 1995. Kidde oil boiler not too difficult to keep running but last remaining service engineer (and source of spares) nearing retirement. No gas available. Oil-fired AGA which we have kept.

 

Had already put in 8kW of solar, EV charging point and Victron/Pylontech ESS so HP the obvious next step.

 

Had some difficulty finding an installer who would not insist on replacing the hard-to-get-at hw tank at great expense. Solved with custom 12kW design from Vaillant with thermal store and two heating zones. Eventually got 6 quotes of which 2 were realistic. Job finally done by Eljay in Ivybridge to a high standard, happy with result.

[Andeh]

7 hours ago, JohnMo said:

If you get that it's just piss poor design from installer not the boiler. Mine was pretty much silent, directly connected to UFH manifold no mixer and pump. Just ran a steady 32 degs, and was managed by a low hysterisis thermostat. When it did DHW it just ramped up slowly to 60 degs, by the time it got the cylinder was at 52 degs.

 

Yeah, I do agree. Context is important.... Last house the boiler was under the master bedroom, and we had a faulty zone valve which triggered it randomly, plumber miss diagnosed it so I lost a lot of sleep with it firing randomly and me being twitched about it.

 

I accept zone valves can do the same to ASHP, but I still carry frustrations over that period of home ownership!

[MikeGrahamT21]

Does anyone worry about the thoughts of replacing the heat pump should it fail? Have just had a look at Vaillants which seem to have 7 year warranty, vs their gas boilers which have a 10 year warranty. Obviously the first install with conversion from gas/oil/lpg gives you the £7.5k grant, but if it should fail out of warranty then essentially its full price for another, the thought of that scares the hell outta me having one. Appreciate in 7 years time they maybe a lot cheaper, but only maybe.

[JohnMo]

11 minutes ago, MikeGrahamT21 said:

Does anyone worry about the thoughts of replacing the heat pump should it fail? Have just had a look at Vaillants which seem to have 7 year warranty, vs their gas boilers which have a 10 year warranty. Obviously the first install with conversion from gas/oil/lpg gives you the £7.5k grant, but if it should fail out of warranty then essentially its full price for another, the thought of that scares the hell outta me having one. Appreciate in 7 years time they maybe a lot cheaper, but only maybe.

I just replace one - the old one is being used for hot tub.  The new one was a mornings work to install - I did install the wiring centre that came with new one, and pre-invest a cable the old unit didn't have. Cost £2100, plus some new insulation near heat pump. If you install a Vaillant you could be 3x that.

 

In 7 years time, grants will not be available, so suspect like solar PV prices, will drop like a stone

Edited 19 hours ago by JohnMo

[MikeGrahamT21]

22 minutes ago, JohnMo said:

I just replace one - the old one is being used for hot tub.  The new one was a mornings work to install - I did install the wiring centre that came with new one, and pre-invest a cable the old unit didn't have. Cost £2100, plus some new insulation near heat pump. If you install a Vaillant you could be 3x that.

 

In 7 years time, grants will not be available, so suspect like solar PV prices, will drop like a stone

So you are saying the bulk of the price is for the initial install and those bits will remain viable for another HP?

 

I guess if thats the case then a replacement HP would maybe only be slightly more expensive than a gas boiler, but would save money in long run (as long as electric prices come down). I wonder how much a company would charge to do all of the work for a replacement unit?

[JohnMo]

5 minutes ago, MikeGrahamT21 said:

So you are saying the bulk of the price is for the initial install and those bits will remain viable for another HP?

 

I guess if thats the case then a replacement HP would maybe only be slightly more expensive than a gas boiler, but would save money in long run (as long as electric prices come down). I wonder how much a company would charge to do all of the work for a replacement unit?

Once a heat pumps heating a heating system, the system stays as is, you are only removing the old heat pump, basically power, communication cable and two flexible pipes. So new heat pump is just a simple reconnect everything to new heat pump. But cost of a Vaillant heat pump can be stupid expensive.

 

As said I did it myself (had assistance moving the new heat pump only) in 5 hours to be exact, from switch off old to switch on new. So a company is likely to charge half a day for plumber, plus electrician or maybe a day each. But who knows.

[Dillsue]

If you got an expensive installer supplied HP now and it fails there's nothing to stop you changing to different manufacturer if and when it fails. For most situations you likely need to change the controller but there's a fair chance the existing controller cabling would work. A replacement for our 7kw LG Therma V is £2700, so not the end of the world if it throws the towel in.

[MikeSharp01]

We started the build as a Passive House but gas fired, we had the gas laid in and ran the track pipe (which is for sale in the market place now.) through a duct from the gas meter. I had looked at ASHP but felt gas was a safer bet, this was at the planning stage in 2017 - we wouldn't need a cylinder so the heat loss into the building, which @Jeremy Harris had shared with us all would not be a problem. I had a very good plumber / gas fitter so fitting the boiler would have been no problem and it should have been a smooth process with a combi boiler. Then I started to get much more concerned about the eco credentials of gas fired heating and decided to look at other options SUNAMP, PV, Willis, and battery but as SUNAMP was getting increasingly bad press and the Willis route would have hit our SAP score they got kicked into touch. So gas came back, but sadly our tame gas fitter was taken ill, and was unable to work, and we would have had to seek someone else so I took a look at ASHP again, plus the grant was now £7500 so we should be able to get it done for that! So in 2021 we started looking at MCS installers and that was like pulling teeth because none of them were very convincing and didn't listen to our design and insulation standards preferring to fall back on some sort of opaque arbitrary process to give us wild quotes for a straight install where a big chunk of the work was already done. The UFH is in and I had installed two 28mm pipes in the insulation from the utility room to the place we might install a heat pump just in case. So again I swithered a bit, and at that point the Umbrella schemes started to take off and it struck me that we might fit the ASHP ourselves if we could find a sound scheme to duck under. In the end after a lot of searching and a bunch of Quality Function Deployment (QFD) like exercises to compare the various offers we went with Cool Energy, although we had to wait almost a year for their smallest Heat Pump to get MCS accreditation. Its installed and commissioned now - still sorting out some teething issues, we have had our grant money and the all up cost with everything including the EMON heat meter system with all the bells and whistles has come in on the money with me doing all the plumbing, electrics and controls and them signing it all off. 

[SimonD]

7 hours ago, MikeGrahamT21 said:

Does anyone worry about the thoughts of replacing the heat pump should it fail?

 

Not really. Theoretically it should be easier than swapping out a gas boiler. Even connecting the flushing equipment is easier as you can do it off the isolators outside.

[SimonD]

6 hours ago, MikeGrahamT21 said:

I guess if thats the case then a replacement HP would maybe only be slightly more expensive than a gas boiler, but would save money in long run (as long as electric prices come down). I wonder how much a company would charge to do all of the work for a replacement unit?

 

You've also got the option of just buying a second hand unit too, which you don't usually get with a gas boiler. Or at least I wouldn't install a second gas boiler for any of my customers.

[-rick-]

2 minutes ago, SimonD said:

You've also got the option of just buying a second hand unit too, which you don't usually get with a gas boiler. Or at least I wouldn't install a second gas boiler for any of my customers.

 

That may be a temporary situation with lots of people getting them, then changing their minds due to poor experience. Things will bed down and at some point there won't be many second hand ones without a lot of use.

[Oz07]

14 hours ago, JohnMo said:

Once a heat pumps heating a heating system, the system stays as is, you are only removing the old heat pump, basically power, communication cable and two flexible pipes. So new heat pump is just a simple reconnect everything to new heat pump. But cost of a Vaillant heat pump can be stupid expensive.

 

As said I did it myself (had assistance moving the new heat pump only) in 5 hours to be exact, from switch off old to switch on new. So a company is likely to charge half a day for plumber, plus electrician or maybe a day each. But who knows.

You're obviously a clever guy but if you seriously think a company are going to send out a plumber and sparks for half a day to switch a heat pump thats insane. Even giving them a full day each I'm not sure its likely. Anyone who does them is going to be that busy creaming money off new installs I can't see them swapping one out on day rate. Anyone who isn't experienced with them and banging them in all the time, then would you really want them swapping it out. 

Edited 3 hours ago by Oz07

[Oz07]

8 hours ago, MikeSharp01 said:

We started the build as a Passive House but gas fired, we had the gas laid in and ran the track pipe (which is for sale in the market place now.) through a duct from the gas meter. I had looked at ASHP but felt gas was a safer bet, this was at the planning stage in 2017 - we wouldn't need a cylinder so the heat loss into the building, which @Jeremy Harris had shared with us all would not be a problem. I had a very good plumber / gas fitter so fitting the boiler would have been no problem and it should have been a smooth process with a combi boiler. Then I started to get much more concerned about the eco credentials of gas fired heating and decided to look at other options SUNAMP, PV, Willis, and battery but as SUNAMP was getting increasingly bad press and the Willis route would have hit our SAP score they got kicked into touch. So gas came back, but sadly our tame gas fitter was taken ill, and was unable to work, and we would have had to seek someone else so I took a look at ASHP again, plus the grant was now £7500 so we should be able to get it done for that! So in 2021 we started looking at MCS installers and that was like pulling teeth because none of them were very convincing and didn't listen to our design and insulation standards preferring to fall back on some sort of opaque arbitrary process to give us wild quotes for a straight install where a big chunk of the work was already done. The UFH is in and I had installed two 28mm pipes in the insulation from the utility room to the place we might install a heat pump just in case. So again I swithered a bit, and at that point the Umbrella schemes started to take off and it struck me that we might fit the ASHP ourselves if we could find a sound scheme to duck under. In the end after a lot of searching and a bunch of Quality Function Deployment (QFD) like exercises to compare the various offers we went with Cool Energy, although we had to wait almost a year for their smallest Heat Pump to get MCS accreditation. Its installed and commissioned now - still sorting out some teething issues, we have had our grant money and the all up cost with everything including the EMON heat meter system with all the bells and whistles has come in on the money with me doing all the plumbing, electrics and controls and them signing it all off. 

That trax pipe is expensive isnt it. I had a place 40 odd metres from the rd. Standard gas connection is only like 32m max or something round here. I built a dwarf wall at the max length point and split the ducting here thinking was gonna need the trax. The gas guys just took it all the way to the house for me without even asking. There was a comment after about how it was over max length, a drink to all the crew seemed to quiet that!

[Dillsue]

1 hour ago, Oz07 said:

You're obviously a clever guy but if you seriously think a company are going to send out a plumber and sparks for half a day to switch a heat pump thats insane. Even giving them a full day each I'm not sure its likely. Anyone who does them is going to be that busy creaming money off new installs I can't see them swapping one out on day rate. Anyone who isn't experienced with them and banging them in all the time, then would you really want them swapping it out. 

That's a very valid view but it would likely be very easy money for any plumber/spark that had done a bit of skills updating ie understood heat pumps

[Oz07]

24 minutes ago, Dillsue said:

That's a very valid view but it would likely be very easy money for any plumber/spark that had done a bit of skills updating ie understood heat pumps

Alright in theory, try finding one in practice.