Experiences of replacing Storage Heaters with Air Source Heat Pump?

[RamblingEclectic]

'm hoping to find others who've had personal experience of having air source heat pump installed to replace electric storage heaters in a house that doesn't already have radiators or a boiler that can give me a clearer idea of what I might be getting myself into.

Currently in the ECO4 grant scheme process, at the stage where they've done the 'checking all the information is accurate and taking room measurement' survey and given suggestions to be confirmed with a technical survey.

My solid wall pre-fab concrete house has an EPC of F and is all electric with very old storage heaters, so practically anything for the heating would be an improvement. The recommendations includes air source heat pump and solar panels. Everything I can find on the process on installing an air source heat pump is either discussing replacing a system with boiler and radiators we don't have - not surprising as that's more typical - or when discussing electric storage heaters just doesn't discuss the installation process beyond getting workers in. The closest I've found is a video by an installer that discusses that it's possible, but significantly more work because they need to install more and some debate around air-to-air vs air-to-water for houses that don't already have the piping or ducting for this, but nothing on what we should expect in the instalment process. They are currently intending an air-to-water as part of the improvement in rating needed for the grants comes from heating the electric immersion heater.

I'm open to it - cause as I said anything would be an improvement, we're already pretty cold - but I'd really like to know what I'm getting into generally, I know the specifics will depend on the results from the technical survey.

I think you have a tough problem there, both in terms of what you need to do and in terms of finding someone with the same experience (I don't).

As you probably know, overall insulation/heat leak of a house is important for heat pumps, because the power they can deliver is more limited than gas boilers.

Air to air sounds like a convenient solution in a small house. The problem is as far as I am aware the installation of air to air is not encouraged as they can also be used for cooling which is not considered environmentally friendly. So I don't know whether it is possible to get grants for air to air.

I think irrespective of whatever heat source/method you use, the key first step is getting good insulation and ensuring your house heat leak is minimised. If it is a small house, and it is possible to insulate well, then you may find that insulating the house effectively and swapping old for modern storage heaters is a far more simple and cost effective option than moving to a heat pump.

So I would also be looking at what grants are available in terms of insulation and what the options are on that, maybe independent of heat pumps.

Have you just moved in, and it's the EPC that recommends these?

If there are neighbours with similar houses, I'd ask as many as possible what they have done to improve the insulation and heating, as they will have been in a similar situation. (I notice that near where my DM lived, a (very) few people in concrete block houses have done external cladding to improve insulation, but they might be builders anyway. I was thinking of asking them at the time, to see if it worked well.)

We have ASHP combined with UFH which was done to replace an elderly boiler and radiators BUT I previously lived somewhere with electric storage heaters so do have experience of them too.

Have found the ASHP considerably better than storage heaters and better than the ancient combi boiler but some of that will be lifestyle and other factors like insulation eg ASHP works brilliantly if you have someone at home most of the day as they're better at continuous low level heat/never getting cold, than the peaks and troughs of having a boiler coming on twice a day.

We have just done exactly that storage heaters and water tank, no radiators or pipes to now a full ASHP system. It is so much better, for the first time in 5 years (since we moved in) I feel warm.
It is a lot of work putting in all the pipes etc and we did it as part of a whole house renovation.
Insulation is the key we have had all the floors up so insulation everywhere underneath, the entire loft space is stuffed and we have external insulation then render. We used the 7500 grant and for us has been a great decision as our house can be insulated properly.
Dont need to heat it high at all and works really well.

Thank you everyone. Smithstreet, what the installation process like in time and disruption. We're very slowly renovating this place, it feels I'm having to wrap my head around project after project. It would be great to get this place warm!

The recommendations are by company (Warma) that the energy provider (Octopus) uses for Eco scheme grants. It partially matches what out EPC that was done in 2020 says.

The EPC recommends: floor insulation, hot water cylinder insulation (done this one), changing to a gas condensing boiler along with solar water heating and solar panels, saying that would take us from a 33 F to a 72 C.

Having talked with some of the neighbours, it seems their properties went gas heating decades ago so sadly that hasn't been much help.

Warma is recommending is Air Source Heat Pump, Solar Panels, Loft Insulation (I've questioned this as I was told in the phone discussion that we had more than the grant pays for, 300mm, and this along with lighting are the only 'very good' on our EPC and the surveyor said the stuff looked new - we think it was put in 2018 when the electrics other than the heating were updated, I've been told this will double checked on the technical survey), and Ventilation improvements. I've been told these would take us from an F to a B.

We had ours done as part of a big renovation so hard to answer as we were living/camping in various rooms while build was on so all disruptive. When they did ours they did it in stages when each particular part of the house was being done they laid the pipes for that bit and at the end fitted radiators and turned it all on. We had no heating or hot water (apart from temp electric shower) for five months. As they have to put all the pipes in from nothing I would guess yes disruptive as they need the floors up but probably something the fitters can advise on better and may be less disruptive ways.

@RamblingEclectic did you get your heat pump installed in the end?

if so how do you find it & how much disruption was there?

Currently in the same situation as you were with storage heaters so looking to upgrade our full heating system

I had exactly that done through the Welsh 'Nest' scheme. It took about 7 days, but that was with a day's gap in the middle before the solar panels could be installed.

It's made an amazing difference... House has gone from freezing after 9am (would need to wear hat, gloves and Oodie inside while working from home) with woodburner on as soon as kids home from school, to 19.5°c steadily all day. Electric cost hasn't changed, but there is a huge saving on not using the woodburner (about £3.50 per evening).

I find the water temperature much lower, we run out after 1 long shower despite a bigger tank. That's the only downside, and we just plan and space out our showers. It's been literally life-changing being in a warm house.

Only thing I wished I had done differently... I thought the ASHP would be on the ground, like my neighbour's one. Instead it was bolted to the wall, and the vibrations are audible. I wish it was on the ground instead.

@MonaChopsis what size tank do you have? We have a water tank currently and have the same problem - there’s not even time for me to wash my hair before the water runs out

@Caitlin991 it's 170 litres... The old one was only about 100l but kept at 65 degrees I think, this one only goes up to 50 degrees which seems to make a huge difference. However it also runs on mains pressure now which doesn't help. When the new bathroom goes in (next decade lol) I'll get a low-flow shower head which should help.

@MonaChopsis I am presuming that if you have an electric shower that heats up the water itself, the temperature would be more predictable, but you pay more for more electricity.
Just to add, the pumps are much more quiet these days.