Heating in winter · hot water all year · one electric system
Air Source Heat Pump Installation
Replace your boiler with an air source heat pump that heats your home and your hot water from the outside air — and pairs naturally with solar panels and battery storage.
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An air source heat pump takes the boiler's job: it heats your radiators or underfloor heating and your hot water, using heat drawn from the outside air rather than a flame. For a company that spends its weeks putting solar panels and batteries on homes, it's the obvious next chapter — heating is the biggest energy load most houses have, and a heat pump is how it goes electric. HCE Ltd now offers air source heat pumps alongside solar panels, battery storage and EV chargers, designed around the same idea: a home that runs, as far as possible, on electricity you generate and store yourself.
Heat pumps also attract more exaggeration than anything else we quote for — inflated efficiency claims, grant promises that skip the conditions, and "no changes needed" surveys done from the kerb. So this page is the straight version: what a heat pump actually is, what the £7,500 Boiler Upgrade Scheme really covers, what the running costs honestly depend on, and — because it's true — the fact that a heat pump is not right for every home. If yours isn't ready for one, we'll say so, and we'll tell you what would make it ready.
Below: how air-to-water heat pumps work, the honest suitability checklist, the grant described accurately, running costs without invented figures, the solar pairing, and the one credential question every heat pump quote should survive. We work with homes in and around the areas we already cover for solar: see our Surrey, Sussex and Hampshire pages.
Quick answer
Air source heat pumps:
- An air-to-water heat pump replaces your boiler: it heats your radiators or underfloor heating and a hot water cylinder using heat extracted from the outside air, per the Energy Saving Trust
- Typically around three units of heat per unit of electricity — three to four in a well-designed system — against roughly 90% efficiency from a modern gas boiler (Energy Saving Trust)
- £7,500 off through the Boiler Upgrade Scheme in England and Wales — £9,000 for eligible oil/LPG homes with no mains gas, until 31 March 2027 — per GOV.UK and Ofgem; the installer applies, not you
- VAT on installing an air source heat pump in a home is zero-rated until 31 March 2027 (then 5%), per HMRC VAT Notice 708/6
- The grant requires an MCS heat-pump-certified installer — a credential question to ask anyone quoting, us included
- Not right for every home: radiators, insulation and cylinder space all matter — and if yours doesn't suit one, we'll say so. Free, no-obligation survey and quote
Regulatory positions: GOV.UK, Ofgem, HMRC and the Energy Saving Trust, verified July 2026 — grant amounts and eligibility depend on your property and circumstances.
What an air source heat pump actually is (and isn't)
An air-to-water heat pump replaces your boiler as the heart of your wet central heating and hot water system. The outdoor unit extracts heat from the air — there is useful heat in air well below freezing — concentrates it through a refrigerant circuit, and transfers it to the water that feeds your radiators or underfloor heating, plus a hot water cylinder for showers and taps. That's the Energy Saving Trust's description of the machine, and it's worth holding onto, because "heat pump" covers two quite different products.
The wall-mounted units on our air conditioning page are air-to-air heat pumps: excellent at heating the air in a room quickly, but they don't do radiators and they usually don't provide hot water — you'd need a separate system for showers and taps. This page is about the air-to-water kind — the one that takes over the whole heating and hot water job, and the one the £7,500 grant is for. If you're not sure which suits your situation, that's a conversation, not a sales script: for some homes a room-by-room air-to-air setup genuinely is the better answer, and we'd rather tell you that than sell you the wrong machine.
And yes, it works in a British winter. Air source heat pumps keep working in sub-zero temperatures — units are typically rated to around −15°C or lower depending on the model, and the current flagship units guarantee operation down to −25°C (Mitsubishi's Ecodan R290 and Vaillant's aroTHERM plus both publish that figure). For context, the coldest air temperature ever recorded in the UK is −27.2°C, at Braemar. What a cold snap costs you is efficiency, not heat: the unit works harder for every degree of lift, which is one of several reasons honest system design matters more than brochure numbers.
Will your home suit one? The honest checklist
Not every home is ready for a heat pump, and hearing that at the survey is a lot cheaper than discovering it after the install. Three things decide most cases:
Radiators and flow temperature. A boiler pushes water around your system at 70°C or more; a heat pump is happiest at 35–55°C, and the lower the flow temperature, the more efficiently it runs. Physics sends the bill for that: at 45°C the same radiator gives out materially less heat — roughly 50–60% of the output it was sized for at 75°C — so some radiators usually need swapping for larger-surface-area models. Often it's the older single-panel radiators that become modern double-panel ones; underfloor heating, which loves low temperatures, is the natural partner. Nobody can tell you which radiators from the kerb. It takes a room-by-room heat-loss calculation — which is not a nicety but a requirement of the MCS heat pump standard (MIS 3005). A quote without one isn't a design; it's a guess.
Insulation. A heat pump runs long and gentle rather than short and hot, so the less heat your house leaks, the better the system performs — and the smaller and cheaper the unit you need. Good insulation is no longer a formal precondition of the grant (that rule went in May 2024), but it's still good physics, and sometimes the honest sequence is: insulate first, heat pump second.
Somewhere for a cylinder. Your hot water will live in a cylinder rather than being made on demand. If a combi boiler cleared out your airing cupboard years ago, finding cylinder space is part of the survey conversation — usually solvable, occasionally the deciding factor.
The honest bottom line: a hard-to-heat house with no cylinder space and radiators that can't be upgraded is genuinely better off fixing those things first. If that's your house, we'll say so — and tell you what would change the answer.
The £7,500 Boiler Upgrade Scheme — described accurately
Grant copy attracts exaggeration, so here is the scheme as GOV.UK and Ofgem actually describe it, verified July 2026.
The amounts. £7,500 towards an air source (air-to-water) or ground source heat pump in England and Wales. And a genuinely new addition: from 21 July 2026 to 31 March 2027, eligible homes heated by oil or LPG with no mains gas connection get £9,000 — an extra £1,500 recognising that off-grid homes have the most to gain from switching. (Air-to-air systems attract a smaller £2,500 grant on a much narrower replacement-only route — covered honestly on our air conditioning page.) The scheme has been extended to run to 2030.
The shape of eligibility. You need to own the property — that includes second homes and properties you rent out. The grant is for replacing an oil, gas, LPG or electric heating system. Most new-build properties, social housing, and properties that have already received government funding for a heat pump are excluded. The old EPC and insulation preconditions have been removed — the rules have changed twice in two years, in homeowners' favour both times — so check the live eligibility page on GOV.UK rather than a blog post's memory of it, and we'll walk through it with you at the survey.
How it's actually claimed — and the question to ask. You don't apply for this grant; the installer does. The scheme requires the installer to be MCS heat-pump certified, the application is made on your behalf, and the system must be commissioned within 120 days of applying. So ask whoever quotes you — us included — exactly how they handle this: who holds the MCS heat-pump certification, who makes the application, and where the £7,500 appears in the written quote. A good answer is specific. A vague one tells you something too.
One more piece of good news while it lasts: installing an air source heat pump in a home is zero-rated for VAT until 31 March 2027, reverting to 5% from 1 April 2027 (HMRC VAT Notice 708/6). Your written quote will show the VAT treatment explicitly, so there's nothing to decode.
Running costs — the honest version
The headline is real: a heat pump typically delivers around three units of heat for every unit of electricity it uses — three to four in a well-designed system — against roughly 90% efficiency from a modern gas boiler. That's the Energy Saving Trust's framing, not ours.
Here's the part most pages skip. The largest real-world trial of heat pumps in the UK — the Electrification of Heat Demonstration Project, 742 installed systems — measured a median seasonal performance factor of 2.80 for air source units (Energy Systems Catapult). Real homes, real winters, real usage. The gap between that 2.8 and the 4-plus in manufacturer lab figures is mostly design and installation quality: flow temperature, radiator sizing, controls, commissioning. Which is exactly why the credential section below exists.
And the electricity-to-gas caveat, plainly: a unit of electricity costs materially more than a unit of gas, so "three times more efficient" does not automatically mean a third of the bill. Against mains gas, whether you save depends on the efficiency your system actually achieves and the tariff you run it on. Against oil, LPG or electric heating, the savings case is much clearer. We're not going to invent an annual figure here — pages that do are guessing at your house, your tariff and your winter. What we will do at the survey is the honest arithmetic for your case, on your numbers.
The solar pairing — a heat pump belongs in an electric home
A heat pump turns heating — the biggest energy load in most homes — into an electrical load. That's our home turf. Solar, batteries and smart tariffs are what HCE does every week, and they're precisely the tools that shrink a heat pump's running costs.
The honest version of the pairing, though, because this is another area where pages overpromise: we won't pretend January heating runs on January sunshine. Winter is when panels generate least and the heat pump works hardest — that's just the shape of the year. What solar genuinely does is carry your hot water and shoulder-season heating for much of the year, and push summer export income against winter running costs. Add battery storage and the choreography extends: cheap overnight electricity charges the battery and heats the house and cylinder in the low-rate window, and your own generation covers more of the rest.
If solar and battery are on your list as well as a heat pump, tell us — designing them together beats bolting them together, the same way it does when solar and an EV charger arrive in stages. And if you already have panels, bring your system details to the survey: they change the arithmetic, in your favour.
What good kit looks like (the benchmark for any quote)
As on our air conditioning page, we'd rather teach you the benchmark than recite a brand list. The current market-leading air-to-water units — the likes of Mitsubishi Electric's Ecodan R290, Vaillant's aroTHERM plus and Daikin's Altherma 3 range — publish specifications that make a useful yardstick for judging any quote, ours included:
- R290 refrigerant on the newest generation — a natural refrigerant with a tiny global warming potential (Mitsubishi publishes a GWP of 0.02 for the Ecodan R290; Vaillant a GWP of 3 for the aroTHERM plus), replacing older, higher-GWP gases.
- Flow temperatures up to 75°C (published by both Mitsubishi and Vaillant for the ranges above) — boiler-like temperatures for hot water and cold snaps, which makes radiator retrofits easier. The efficiency sweet spot is still low and slow; the headroom is there for when you need it.
- Guaranteed operation down to −25°C (Mitsubishi Ecodan R290; Vaillant aroTHERM plus) — comfortably below anything a UK winter has ever produced.
- Published SCOPs around 4 to 5 — Mitsubishi publishes a SCOP of 4.42 for the 5kW Ecodan R290; Vaillant publishes up to 5.03 for the aroTHERM plus. Treat these as manufacturer lab figures: the real-world median across 742 UK installs was 2.80, and design quality is most of the difference.
- Quiet running — Vaillant publishes sound power as low as 54 dB(A) for the aroTHERM plus, with Quiet Mark accreditation on all but the 10kW model. Outdoor-unit siting still matters; that's a survey job, neighbours included.
- Monobloc or split — monobloc units (everything sealed in the outdoor box, only water pipes entering the house) are the common domestic route; genuine split systems exist for specific siting situations (Daikin's Altherma 3 range includes both). Outputs run roughly 3.5–12 kW across these ranges, and the survey's job is to size the unit to the heat-loss calculation — the right number, not the biggest one.
One warranty honesty note, because nobody else will tell you this: none of the big manufacturers offers a flat consumer warranty. Mitsubishi's Ecodan warranty runs up to 3 years as standard, up to 5 via its Accredited Installers and up to 7 via its Business Solutions Partners; Daikin gives 2 years as standard, extendable to 5 free of charge via Stand By Me registration with verified annual maintenance, and to 7 only as a paid extension through a Sustainable Home Expert installer. So "what's the warranty?" really means: what's your tier with this manufacturer, and what registration and servicing keeps it valid? Get the answer in writing — from us or anyone else.
We'll confirm the specific makes and models being quoted at quote stage, in writing, with the published datasheet figures alongside. The brands above are cited as the market benchmark, not as partnerships.
The MCS question — one credential check every heat pump quote should survive
On our air conditioning page we teach the F-Gas check. Heat pumps have an exact equivalent, and it's worth two minutes of your time.
What the scheme requires of any installer. The £7,500 Boiler Upgrade Scheme only pays out when the installation is carried out by an MCS heat-pump-certified installer, who applies for the grant on the homeowner's behalf (GOV.UK). MCS certification is scope-specific: a firm certified for solar panels is not, by that fact, certified for heat pumps — each technology is its own certification. And the MCS heat pump standard, MIS 3005, requires a room-by-room heat-loss calculation before the system is designed — the single document that separates an engineered quote from a guess.
Where we stand, plainly. HCE's own MCS certification is for solar PV — a different scope. For heat pumps, the certification that matters is heat-pump scope, and whoever quotes you — us included — should tell you without being chased exactly how it's covered on your job: certified in their own right, or delivered with a certified partner, and either way, whose name goes on the MCS certificate and the grant application. You'll get that answer from us in writing, before you commit to anything.
So the three questions to ask anyone quoting for a heat pump: Are you MCS certified for heat pumps — you, or a named partner? Who applies for the Boiler Upgrade Scheme grant on my behalf? And show me the room-by-room heat-loss calculation before I sign. A good installer won't blink at any of them. It's a better filter than any review score, because it's checkable.
What does the job involve?
A heat pump installation is a heating redesign, not a box swap. Here's the shape of it.
- Step 1
Survey and heat-loss design
Every room gets a heat-loss calculation — the MIS 3005 requirement — alongside a radiator audit (which stay, which upsize), cylinder siting, the outdoor unit's position (airflow, noise, neighbours, and the planning check for your address), and what your electrical supply needs. This is also where we'll tell you if a heat pump is the wrong answer for your home right now — it happens, and you'd rather hear it at the survey than after the install.
- Step 2
The written quote
Itemised, with nothing to decode: the unit and cylinder, any radiator upgrades, controls, the Boiler Upgrade Scheme grant shown against the price with the MCS certification and application route named, the VAT treatment shown explicitly — and exactly who carries out each part of the work, stated plainly.
- Step 3
Installation, commissioning and handover
The outdoor unit onto its base, the cylinder in, any radiator swaps, then the system filled, balanced and commissioned properly — commissioning is where good heat pumps are made. You get the controls demonstrated before anyone leaves, plus the paperwork pack: commissioning records, the MCS certificate the grant route requires, and warranty registration. It's a bigger job than a boiler swap, and the survey will give you a real schedule for your house, not an optimistic one.
Air source heat pump FAQs
How much is the Boiler Upgrade Scheme grant — and who applies for it?
£7,500 towards an air source (air-to-water) heat pump in England and Wales — and from 21 July 2026 to 31 March 2027, £9,000 for eligible homes heated by oil or LPG with no mains gas connection (GOV.UK and Ofgem, verified July 2026; the scheme now runs to 2030). You don't apply; the installer does. The scheme requires an MCS heat-pump-certified installer, who applies on your behalf and must commission the system within 120 days. The broad eligibility shape: you own the property, the heat pump replaces an oil, gas, LPG or electric heating system, and most new-builds, social housing and properties that already had government heat-pump funding are excluded — the old EPC and insulation preconditions have been removed, so check GOV.UK's live eligibility page rather than an old article. Ask whoever quotes you — us included — who holds the MCS certification, who makes the application and where the grant appears in the written price.
Does an air source heat pump work in a British winter?
Yes — this is the most durable myth in the field. Heat pumps keep working in sub-zero temperatures: units are typically rated to around −15°C or lower depending on the model, and current flagship units guarantee operation down to −25°C per their manufacturers' published data. The coldest air temperature ever recorded in the UK is −27.2°C, at Braemar — a once-in-history extreme, not a winter. What cold weather actually costs is efficiency rather than heat: the unit works harder for each degree of lift, which is why proper design matters — the system is sized to your area's design outdoor temperature as part of the MCS-standard heat-loss calculation, not to a mild day.
Will it actually save me money on heating?
Honestly: it depends what you're switching from, and anyone who quotes you an annual saving before surveying your house is guessing. The efficiency is real — around three units of heat per unit of electricity, three to four in a well-designed system, versus roughly 90% for a modern gas boiler (Energy Saving Trust) — but a unit of electricity costs materially more than a unit of gas, so against mains gas the result depends on the efficiency your system actually achieves and the tariff you run it on. The UK's largest real-world trial measured a median seasonal performance factor of 2.80 (Energy Systems Catapult, 742 homes): well-designed systems beat that comfortably, badly designed ones don't, and design quality is the whole game. Replacing oil, LPG or electric heating, the case is much clearer. Solar panels and battery storage shift the sums further in your favour. At the survey we'll run your numbers on your tariff — including, if it's true, the answer that you shouldn't do it yet.
Will I need new radiators?
Some, usually — and be wary of anyone who promises otherwise before measuring. A heat pump runs your system at 35–55°C rather than a boiler's 70°C-plus, and at those temperatures the same radiator emits materially less heat — roughly 50–60% of the output it was sized for at 75°C. So radiators in some rooms typically need swapping for larger-surface-area models; often it's the older single-panel radiators that become modern double-panel ones, and underfloor heating needs no changes at all. Which rooms, exactly, is what the room-by-room heat-loss calculation determines — a requirement of the MCS heat pump standard (MIS 3005), not an optional extra. Radiator changes belong itemised in the written quote, not discovered on installation day.
Do I need planning permission for the outdoor unit?
For most houses in England, no — heat pump installations normally fall under permitted development, and the rules were relaxed further in May 2025 (legislation.gov.uk). Conditions still apply — the unit's siting and size, and extra restrictions for listed buildings and conservation areas — and Wales and Scotland have their own rules, so it gets checked properly for your address at the survey rather than assumed from a national summary. The outdoor unit's position is usually decided by airflow, pipe runs and being a good neighbour on noise long before planning becomes the constraint; siting is a survey job, and one worth doing well.
Ready for a boiler that doesn't burn anything?
Request a free, no-obligation survey and you'll get the honest version: whether your home suits a heat pump at all, what it would really cost to run on your tariff, and what the £7,500 grant genuinely covers — designed alongside solar panels and battery storage if you want the full electric picture. If the honest answer is "not yet", that's the answer you'll get. No pressure, just clear advice.
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