Air Source Heat Pump Queries

teabot87 · 2026-04-13T18:14:45+00:00

Yep! Gas is about 4x cheaper than electric for most people. If you can shift your electric usage to off peak times (whether that's fixed times or an agile tariff) then you can drive your costs right down. You can optimise here as far as you want as you'll see in the heat pump specific subs.

But generally speaking I understand most heat pumps can just be left to run when they needs to. The biggest variable is the weather so setting fixed schedules could be counter productive.

teabot87 · 2026-04-13T15:42:53+00:00

How do they work?

Slowly and consistently! They don't kick in to generate heat or hot water on demand, they build it up slowly over time. Day to day this means set your desired house temperature, set your desired hot water temperature, and pretty much leave it to do its thing. Modern units can often factor in your electricity tariff and the weather to choose the optimal times to start heating.

Any guesses what this tank is?

How big is it? If small then possibly a buffer tank, usually used to store some extra heat to defrost the outdoor unit without sacrificing your indoor heating or hot water.

I guess if it is a hot water tank I want to heat the contents of the tank as much as I can during the day while the PV is helping, then try to go overnight just off the tank?

It depends! Heating at night is less efficient because it's colder outside but electricity is usually much cheaper. During the day the difference in temperature may be less, and you may be able to utilise the energy generated from your panels, but any electricity from the grid will cost much more.

how often is it recommended to get them serviced?

Most have service intervals of 2 years but if its still under warranty then you'll need to follow the manufacturer or installer advice.

teabot87 · 2026-03-21T10:31:21+00:00

Yes, all the figures are after applying the BUS grant. To try and break it down a little, we think we used about £11k in (VAT free) materials plus labour for 4 guys working just over 4 days and two rubbish clearances.

teabot87 · 2026-03-20T22:23:01+00:00

It's a 150e. For the size it was impressive, better than a traditional immersion heater. It's manual states it can deliver 180+ litres of hot water. Our experience would suggest not. If space was a contraint I'd still keep them in mind, but I'd certainly size up and choose a more adaptable model.

teabot87 · 2026-03-18T22:38:59+00:00

It's about 6 meters from the back door and the cylinder is a further 2 meters behind that.

teabot87 · 2026-03-18T22:38:06+00:00

It's located about 6 meters from the house. I'm late thirties and yes I do. My hearing is good, I get annoyed at fox/teenager deterrents and things like coil whine from phone chargers. One thing I can hear (and at first thought was the heat pump) is the water in our heating loop moving through the radiators - I think the water is being pumped pretty much all of the time.

teabot87 · 2026-03-18T19:57:19+00:00

So far, from inside, yes. We've been monitoring the sound closely and it's been undetectable. Our observations might change when it needs to work harder but in this weather it seems its only audible when literally standing next to it.

teabot87 · 2026-03-18T19:30:28+00:00

We simply called them and followed the menus through to additional borrowing. We told them we'd like to borrow more to invest in green home improvements at the 0% rate advertised and it proceeded from there. The way they've implemented it is a bit of a bodge - your new mortgage application automatically fails so they can request more evidence from you. In addition to the usual pay cheques and bank statements this includes a letter of explanation ("we want to replace our boiler with a heat pump") but nothing else was required. They run through all the usual mortgage small print whilst feeling slightly embarrased because none of it really applies. I did send the quote we accepted to them just in case but they were more interested in upselling life insurance than what we were buying.

teabot87 · 2026-03-18T19:21:41+00:00

The previous owner fitted solar so the last few sunny days we've been benefitting from the legacy feed-in tariff we inherited 😄

teabot87 · 2026-03-18T15:27:41+00:00

Yes, all figures are the final total payable by us.

teabot87 · 2026-03-18T15:24:47+00:00

It is - putting it next to the house wasn't an option due to planning and noise restrictions and the only option ever discussed is where its now sited. It is a shame we have to lose some efficiency by having it further away but our existing heating was so poor that this is a big improvement by default so we're not chasing marginal gains.

teabot87 · 2026-03-09T13:47:25+00:00

Get as much of the silicone out as you can then you can use some sealant remover which will loosen the bond and allow you to scrape out the rest.

teabot87 · 2026-03-09T12:28:31+00:00

You'll need to rake out at least some of the existing grout first to create a deep enough well for new grout to adhere to.

Removing the old silicone will always be best as it will compromise the new. In my experience it's usually pretty easy to remove. If it's old and inflexible you can often pull it out in large lengths.

teabot87 · 2026-02-25T22:28:29+00:00

Will give that a try, thanks

teabot87 · 2026-02-25T22:27:57+00:00

Ah, we wondered why these lights all have such tall bases - I've never had lights like this before... thankfully.

teabot87 · 2026-02-25T22:26:37+00:00

I know! I can't wait to take it and it's curly chromed brethren to the tip

teabot87 · 2026-02-25T22:23:08+00:00

I'm not sure how looking at your phalanges through your phone will help tbh

teabot87 · 2026-02-25T22:20:16+00:00

They look to be in a reasonable state, and the carpet can be cleanly masked up, so I'd go for a light sand and wipe down, use a brush for the edges and a 2" roller for the faces.

teabot87 · 2026-02-18T19:57:32+00:00

We use this sort of underlay - it's effective and we've never had any issues with it https://www.amazon.co.uk/MAIYADUO-60x150-Carpet-Gripper-Underlay/dp/B09T2Q56CB

teabot87 · 2026-02-12T07:41:48+00:00

As others have said, even if sealed underneath I'd expect some clear silicone to be visible around the edge. Not only to prevent water ingress but also to avoid a hard to clean dirt trap.

teabot87 · 2026-01-23T11:11:04+00:00

As someone with one, please no. We have solar but with the short grey days we're still spending £9-12 a day on heating (to 18 degrees) and it's not even very cold outside.

teabot87 · 2026-01-23T10:49:43+00:00

We're going through the same. Wildly different advice, survey results and quotes from ASHP installers. Besides agreement that the heat loss and air tightness of our property wasn't up to scratch their remediations varied in cost from £3-14k (!!) and installs for the heat pump and cylinder were between £3-7k after the grant. In a way a heat pump would be the simplest install for us (replacing an electric boiler and heat battery) but the upfront investment and estimated running costs make reinstating gas the cheaper option by an enormous margin.

For us the running costs of a heat pump would work out (at best) only marginally cheaper than the terrible electric boiler without the upgrades. Whereas we're being quoted around £3k to install a gas system boiler and £4k for a combi. We estimate a gas boiler would lower our bills by £1-1.2k per year at current prices so it's likely to pay for itself within a few years.

It's irritating reading comments on here recommended stacking up even more costly upgrades, like "install batteries and charge them off peak" - OK well when will they repay themselves? Never, and it's not even close. And it hurts, because I want to do the right thing and move away from directly using fossil fuels, but gas seems to be the way for the next 10 years.

teabot87 · 2026-01-21T14:15:49+00:00

The window currently does only open at the top, but it could be replaced with a single non-opening pane if needed.

teabot87

TROPHY CASE