The Short Answer
Get at least three quotes, and judge them on what's in them, not just the price. A proper quote names the exact heat pump model and kW output, comes from an installer with an MCS certification number you can check, and is backed by a design based on a room-by-room heat loss calculation, with a design flow temperature and a performance estimate. If a quote is missing those, it isn't cheap, it's incomplete. MCS lets the room-by-room figures, flow temperature and SCOP come after signing, as long as you have them before installation, but we'd get them before you sign.
On price, the middle half of real air source installs in April to June 2026 came to about £3,600 to £8,100 after the £7,500 Boiler Upgrade Scheme deduction (England and Wales; in Scotland it's Home Energy Scotland, and Northern Ireland has no BUS). Bigger heat pumps cost more, so check your own quote against its size in the checker below. And never pay more than 25% up front.
Heat pump quote checker
Is your heat pump quote fair?
We compare it with what households paid for the same size of heat pump under the Boiler Upgrade Scheme.
Is that price
Households who had an air source heat pump of 6 to under 8kW fitted paid a median of £12,164 before the grant (8,054 installs in 2025/26). On our estimate, the middle half paid about £10,500 to £14,700.
Enter your quote above to see where it sits.
Does your quote include all of this?
Free, no obligation. Get at least three quotes, as MCS and the Renewable Energy Consumer Code advise.
Source: DESNZ Boiler Upgrade Scheme statistics, August 2026 (installations with a paid voucher, England and Wales), tables A1.3A (median by capacity, 2025/26; bands include the lower bound) and Q1.1A (quartiles, all sizes, April to June 2026). The typical range for each size is the national spread scaled to that size's median. Air source, air-to-water only.
Why Heat Pump Quotes Vary So Much
Gas boiler quotes are easy to compare because the job is roughly the same everywhere: take the old one off the wall, put a new one up. Heat pump quotes aren't like that. Two installers can look at the same three-bed semi and propose different sized units, different cylinders, a different number of radiator swaps and a different flow temperature. Every one of those choices changes both the price today and your running costs for the life of the system.
So don't be surprised if your quotes are a few thousand pounds apart. That's normal. What isn't normal is quotes that differ because one installer skipped the design work. A quote can be cheapest because nobody has worked out what your house actually needs, and you find that out in January.
The goal isn't to find the lowest number. It's to find the quote where you can see exactly what you're paying for, and where the design is good enough that the heat pump will run efficiently. A well-designed system at £5,900 after the grant beats a badly designed one at £3,600 every single winter.
What a Proper Quote Must Include
This isn't us being fussy. Most of what follows is written into MCS's own rules. MCS publishes Guidance for Contracts and Quotations and the heat pump design standard, MIS 3005-D, and between them they spell out what you're entitled to see.
Before you sign
- The installer's MCS certification number. MCS says a quote should include it. No number, no grant, because the Boiler Upgrade Scheme only works through MCS certified installers.
- The exact make and model of heat pump, with its output in kW, plus the manufacturer's datasheet. "7kW air source heat pump" isn't enough. You want "Vaillant aroTHERM plus 7kW" or similar, so you can look it up.
- The hot water cylinder: make, model and size, plus its datasheet. Most homes coming off a combi will need one.
- A performance estimate. MIS 3005-D requires the installer to give you an estimate of the system's annual energy performance, along with a Key Facts sheet, before the contract is awarded. This is where the predicted running cost comes from.
- A full cost breakdown covering labour, materials and equipment, with the total including and excluding VAT.
- The Boiler Upgrade Scheme grant shown as a deduction. gov.uk is explicit: the grant "will be taken off the amount you pay for installation. This will be shown on your quotation and invoice."
- The deposit, any staged payments, and how the deposit is protected. MCS lists all three as things a quote should contain.
- Warranties and guarantees, and how long each lasts: the heat pump, the cylinder and the installer's own workmanship.
- Timings: how long the job takes and when it can start.
- How long the quote is valid for.
- Any subcontractors who'll do part of the work. MIS 3005-D requires them to be named up front.
Before the work starts
Some of the detailed design can come after you've agreed the contract, but MIS 3005-D says you must have it in writing before installation begins:
- The heat loss of every room (in watts per square metre). This is the proof that someone did a room-by-room calculation rather than guessing from the floor area. To sense-check the total before the survey, run your home through our heat pump size calculator.
- The design flow temperature: the temperature of the water leaving the heat pump.
- The SCOP at that flow temperature, taken from the MCS website.
- The type and size of every radiator (or other emitter) in the system.
- How much hot water you use a day, as calculated, and how quickly a new cylinder heats back up after a bath or shower.
If the design changes the estimated performance or the agreed spec, the installer has to give you an updated estimate, a written variation to the contract, and the chance to cancel without further cost. That's worth knowing if the survey turns up something unexpected.
The one question that sorts good installers from bad: "What's the design flow temperature, and what's the SCOP at that temperature?" A good installer answers straight away. Someone who says "it'll be fine" or talks about 60C is telling you the system hasn't really been designed.
A Worked Example: Reading a Quote Line by Line
Here's what a sensible quote for a typical three-bed semi, currently on a gas combi, might look like (our example). Before the radiators, it lands on the £12,200 or so that a typical 6 to 8kW install really costs, going by the DESNZ Boiler Upgrade Scheme statistics. DESNZ doesn't say whether radiator work is in its figures, so we've put three radiators on top. The ranges match our heat pump costs guide. Yours will differ, but the structure is what you should be looking for.
| Line item | Example | Typical range (our estimate) | What to check |
|---|---|---|---|
| Heat pump unit | £5,800 | £3,000 to £7,000 | Exact model and kW named, datasheet supplied, an MCS certified product |
| Hot water cylinder | £1,400 | £500 to £1,500 | Size matches your household, heat pump rated coil |
| Radiator upgrades (3 rooms) | £1,200 | £0 to £2,800 | Only the rooms the heat loss calculation says need it |
| Installation labour | £3,700 | £2,000 to £4,000 | Number of days, who does the electrics |
| Electrical work | £500 | £300 to £800 | Consumer unit, isolator, dedicated circuit |
| Pipework, controls, commissioning | £800 | £0 to £1,500 | Weather compensation set up, MCS certificate included |
| Total before grant | £13,400 | About £11,100 to £15,600 (the middle half of real installs, DESNZ BUS statistics, April to June 2026) | VAT on the heat pump installation should be 0% (the energy-saving materials relief runs to 31 March 2027). Unrelated extras billed separately can carry 20%, so ask if you see VAT |
| Boiler Upgrade Scheme grant | minus £7,500 | £7,500 | Deducted on the quote, installer applies |
| You pay | £5,900 | About £3,600 to £8,100 | Deposit no more than 25% of this |
Two things jump out when you read quotes this way. First, the heat pump itself is under half the cost (about 43% in our example), so a quote that looks cheap because of a cheaper unit may have cut corners somewhere much more important. Second, radiators are a big place for quotes to diverge. One installer says you need six new radiators, another says two. The room-by-room heat losses are how you settle it. See do I need new radiators for a heat pump for what's genuinely needed.
If you only have one quote and can't tell whether it's fair, that's exactly the point of getting a second. Get another quote from MCS installers near you and lay them side by side against this table.
Red Flags That Should Make You Walk Away
- No survey, or a quote from photos alone. A room-by-room heat loss calculation needs measurements from every room. Someone who quotes you a fixed price over the phone hasn't done it, and the MCS standard says the building has to be assessed by a competent professional experienced in heat pump systems.
- A unit that's much bigger than the others are quoting. If two installers say 6kW and one says 12kW, ask why. The standard requires the heat pump to cover at least 100% of the calculated heat load, but a unit well above that costs more to buy and can cycle on and off rather than run steadily.
- A high flow temperature with no explanation. If the design goes above 55C, MIS 3005-D says the installer should also give you an alternative design at 55C or lower and explain the differences in efficiency and energy use so you can choose. If they haven't, ask for it.
- The grant isn't on the quote. The £7,500 should appear as a deduction. "Pay us the full amount and claim it back" is not how the scheme works.
- A big deposit. The Renewable Energy Consumer Code's advice is plain: never pay more than 25% as a deposit, and make sure it's insured.
- Pressure to sign today. "This price is only valid if you sign now" is a classic. RECC's advice is not to accept any offer of a discount for signing there and then, and the MCS Customer Commitment says installers must not pressure you to sign.
- A running cost promise tied to one tariff. MCS requires installers to warn you not to sign a contract based on specific energy prices, because tariffs change.
- Buffer tanks, extra controls or "premium" add-ons that the others haven't included and nobody can justify. Ask what each one does for your house specifically.
How to Check an Installer Is MCS Certified
Don't take the logo on the van as proof. MCS has a free Find an Installer tool where you can search by company name or certification number. Check three things:
- The company is listed and the certification is current.
- It's certified for air source heat pumps specifically, not just solar.
- The name and number match what's on your quote.
Also ask whether they're a member of a consumer code, RECC or HIES. This used to be automatic with MCS, but it isn't any more. Under MCS's redeveloped installer scheme, which most installers are moving onto during 2026, consumer code membership is no longer mandatory. Some installers keep it anyway, so ask. Members of RECC must insure deposits and any other advance payments, and back their workmanship guarantees with insurance, so you're covered if the firm stops trading.
In place of the consumer code, the redeveloped scheme makes every installer buy an MCS approved financial protection product on your behalf. It pays to put right a faulty installation if the original installer won't or can't (because it's gone bust, say). It lasts at least six years, and the excess is capped at £250. That's good cover for the work itself, but it's about fixing the installation, not refunding a deposit. So whichever scheme your installer is on, ask them to explain in writing how your deposit is protected. MCS says they have to tell you, and the quote should name the financial protection product too.
Our installer directory lists MCS certified heat pump installers by area, which is a quick way to find a second or third firm to compare against.
Questions to Ask Every Installer
- Can I see the room-by-room heat loss figures?
- What's the design flow temperature, and what's the SCOP at that temperature?
- Which radiators need replacing, and why those ones?
- Will you set up weather compensation, and will you come back and tune it after the first cold spell?
- Where will the outdoor unit go, and have you done the noise check for permitted development? (In England and Wales the limit is 37.0 dB LAeq,5mins, measured 1m outside a neighbour's habitable-room window or door; see our noise guide.)
- Who applies for the Boiler Upgrade Scheme grant, and when?
- How much deposit do you need, and how is it protected?
- What warranty comes with the heat pump, and is the workmanship warranty insurance-backed?
- Is the first service included, and what does an annual service cost after that?
- Do you use subcontractors for any part of the job?
A good installer will be pleased you asked. The ones who get defensive have usually just told you something.
Why Three Quotes, Not One
Both MCS and RECC say it: get at least three quotes. With one quote you have nothing to measure against. With two, you know they're different but not which one's off. With three, patterns show up. If two installers say 7kW and three radiators, and the third says 12kW and eight radiators, you know which one to question.
Watch out for what we'd call quote fatigue. After the second survey visit it's tempting to go with whoever feels easiest. Don't. The difference between a good and a mediocre design is about £120 to £130 a year in running costs on a typical 3-bed (SCOP 3.5 against 3.0, our model), every year for the life of the system.
If you're weighing up a big supplier's fixed-price package against local firms, read our Octopus heat pump review first. National packages can be good value, but you should still compare them against at least one independent quote.
Only got one or two quotes so far?
Tell us about your home and we'll pass your details to installers who cover your area (check each one's MCS number, as above), so you've got something to compare against. It's free and there's no obligation.
The Checklist
Print this, or keep it open on your phone while you go through each quote. Every box should be ticked before you sign.
- Installer's MCS certification number is on the quote, and checks out on the MCS website for air source heat pumps
- Exact heat pump make, model and kW output, with datasheet
- Hot water cylinder make, model and size, with datasheet
- Performance estimate and Key Facts sheet supplied before signing
- Itemised costs: unit, cylinder, radiators, labour, electrics, pipework
- £7,500 Boiler Upgrade Scheme grant shown as a deduction, installer applying
- Deposit no more than 25%, with written details of how it's protected
- Warranties listed: heat pump, cylinder and workmanship, with lengths, plus any MCS approved financial protection product named
- Start date, job length and quote validity period
- Any subcontractors named
- Room-by-room heat losses, flow temperature and SCOP in writing (MCS only requires them before work starts, but we'd get them before you sign)
- No pressure to sign, and cancellation rights explained
After You've Chosen
Once you've agreed a quote, the installer applies for the grant on your behalf and Ofgem contacts you to confirm the installer is acting for you. Reply to it: Ofgem asks you to confirm within 14 days and may reject the application if you don't. After installation, the installer should register the job and send you an MCS certificate. MIS 3005-D gives them 10 working days after commissioning, and installers on MCS's redeveloped scheme get 30 days, so chase it if you've heard nothing after a month. Keep it with your handover pack: it's the record that the system was installed to MCS standards.
Timing matters too. Ofgem's rules say the heat pump must be commissioned no more than 120 days before the voucher application is made, so the grant must be applied for before the install or within 120 days of commissioning. A good installer will sort this out as a matter of course. For the full process, see our Boiler Upgrade Scheme guide.
