How to choose a heat pump installer: 12 questions to ask
Only MCS-certified installers can claim the £7,500 grant. The 12 questions to ask, a quote comparison table and the red flags to walk away from.
Numbers checked against official sources on 7 October 2026
In 30 seconds
- Only an MCS-certified installer can claim the £7,500 Boiler Upgrade Scheme grant for you. Check the certificate in the official MCS directory.
- Get quotes from more than one installer, as GOV.UK recommends. Three is a sensible number.
- A good quote starts with a room-by-room heat loss survey and states the design flow temperature, the expected efficiency, every radiator change and the grant.
- Walk away from pressure selling, quotes without a survey and requests for a large upfront deposit.
The installer matters more than the brand of heat pump. Two homes with the same unit can have very different bills depending on how well the system was designed and set up. This checklist turns GOV.UK’s official advice and the lessons from real installations into twelve questions you can put to every installer, and the answers you should expect.
On this page
Where to find installers
Start with the MCS installer directory. MCS (the Microgeneration Certification Scheme) certifies heat pump installers and products, and certification is required for the Boiler Upgrade Scheme. GOV.UK also says MCS installers must register with a consumer protection scheme such as RECC or HIES (GOV.UK).
Some energy suppliers and national companies install heat pumps too. They should be MCS-certified in the same way. Wherever you look, check the company’s certificate number in the MCS directory yourself rather than relying on a logo on a website or a van.
The 12 questions to ask
About the design
- Will you do a room-by-room heat loss calculation, and can I have a copy?
Expect: yes, from a visit to your home, with a figure for each room. A size picked from the number of bedrooms is a guess. - What flow temperature is the system designed for, and what efficiency (SCOP) do you expect?
Expect: a specific figure. Lower flow temperatures generally mean higher efficiency and lower bills. - Which radiators will you change, and why?
Expect: a list by room. This is where quotes differ most, and where a cheap quote can hide a cold house. - Where will the outdoor unit and hot water cylinder go?
Expect: a proposed location for both, with how they meet noise rules and the space you have. - What changes to my home would let you fit a smaller heat pump?
This is one of GOV.UK’s suggested questions. A good installer will mention insulation or draught-proofing if it would make a real difference.
About the installation
- How long will the work take, and how long will I be without heating or hot water?
Also from GOV.UK’s list. Ask for the number of days on site. - Does my electricity supply need upgrading, and who pays?
Some homes need a new fuse or consumer unit. It should be in the quote, not a surprise later. - Will you do the whole job, or will other trades be involved?
Ask who is responsible for electrics, plastering and making good. - Can you self-certify the work under a Competent Person Scheme?
GOV.UK suggests asking this, so building regulations paperwork is handled.
About money and protection
- Does the quote show the full price, the grant and what I pay?
GOV.UK says the grant must appear on your quote and invoice. Compare quotes on the same basis. - How much deposit do you need, and is it protected?
Ask how your deposit and workmanship are protected if the company stops trading, for example through an insurance-backed guarantee. - What warranties come with the unit and the work, and how often does it need servicing?
Manufacturer warranties often depend on annual servicing. Ask what it costs and who does it.
Line your quotes up side by side
Copy this table into a notebook or spreadsheet and fill in one column per installer. If a quote leaves a row blank, ask for it.
| What to compare | Quote A | Quote B | Quote C |
|---|---|---|---|
| MCS certificate number checked | |||
| Heat loss (kW) from a room-by-room survey | |||
| Heat pump size (kW) and model | |||
| Design flow temperature (°C) | |||
| Expected efficiency (SCOP) | |||
| Radiators changed (number and rooms) | |||
| Cylinder size and location | |||
| Electrical work included | |||
| Full price | |||
| Grant deducted | |||
| What you pay | |||
| Deposit and how it is protected | |||
| Warranty: unit / workmanship | |||
| Servicing interval and cost |
Red flags
- No home visit, or a price given over the phone from your house type alone.
- Pressure to sign today, “today only” discounts or cold calls about “free heat pumps”.
- A large upfront payment before any work is done.
- Vague answers about flow temperature, efficiency or which radiators change.
- A hybrid system (gas boiler plus heat pump) sold as eligible for the grant. Hybrids are not eligible for the Boiler Upgrade Scheme.
- No MCS certificate number, or one that doesn’t match the company name in the directory.
How long the process takes
Allow several weeks from first contact to a working system: surveys and quotes, the grant application, ordering equipment and the installation itself. Once the installer applies for the grant, the heat pump must be installed and commissioned within 120 days, according to GOV.UK. Ofgem will contact you to confirm the installer is acting for you.
Plan around two deadlines on 31 March 2027: the end of 0% VAT on installation, and the end of the £9,000 rate for oil and LPG homes. More on the VAT change.
After the installation
- Ask for your MCS certificate. GOV.UK says you should receive it within 10 days of the installation being completed.
- Ask for a handover: how the controls work, the recommended settings, and what not to change.
- Keep the commissioning record and warranty documents together, and book the first service.
- Check that your home insurance covers the new system, which GOV.UK also recommends.
Got a quote with an efficiency figure? Put it into the calculator to see the running cost against your boiler.
Open the calculatorFrequently asked questions
How many heat pump quotes should I get?
GOV.UK recommends quotes from more than one installer. Three gives you a good sense of the range, as long as each is based on a survey of your home.
How do I check an installer is MCS-certified?
Search for the company in the MCS installer directory at mcscertified.com and check that the certificate number and company name match what they gave you.
Why are heat pump quotes so different?
Mostly because of radiator changes, the size of the unit, the cylinder and what extras are included. Comparing each quote’s heat loss figure, flow temperature and radiator list explains most of the gap.
What happens if my installer goes out of business?
That is what deposit protection and insurance-backed guarantees are for. Ask each installer what protection applies before you pay anything.
Should the cheapest quote win?
Not automatically. A cheap quote that skips radiator changes can leave you with a heat pump that runs inefficiently for 20 years. Compare the design, not just the price.
