How Do I Choose a Heat Pump Installer?

Choose a heat pump installer who is MCS certified for heat pumps and who sizes the system from a room-by-room heat loss calculation of your home, not from the size of your old boiler. Once those two boxes are ticked, compare written quotes line by line, check how your deposit is protected, and ask what support you get after the engineers leave.

Certification tells you a company is allowed to do the work. The survey and the quote tell you whether it will do the work well in your house. Below you will find both, plus a table of warning signs and a checklist to use before you sign.

What Accreditations Should a Heat Pump Installer Have?

At minimum, a heat pump installer should hold MCS certification for heat pumps, because without it you cannot get the Boiler Upgrade Scheme grant in England and Wales or the Home Energy Scotland grant. MCS has its own article on our site, so here is the short version: it is the UK quality mark for small-scale renewables, and installers are assessed against its heat pump design and installation standards.

Beyond MCS, look for consumer protection cover and, ideally, manufacturer accreditation for the brand being quoted. The table below shows what each one means in practice.

What Are RECC and HIES, and Do I Still Need Them?

RECC (the Renewable Energy Consumer Code) and HIES (the Home Insulation & Energy Systems Contractors Scheme) are the two consumer codes that Ofgem accepts for the Boiler Upgrade Scheme, and most heat pump installers have belonged to one of them. Both set rules on how installers sell, what goes in the contract and how deposits are protected. RECC is approved by the Chartered Trading Standards Institute.

The rules changed in 2026. On 18 June 2026 the Department for Energy Security and Net Zero recognised MCS’s redeveloped installer scheme as a code of practice for the Boiler Upgrade Scheme. Installers certified under that scheme no longer need consumer code membership. Installers still on the older MCS scheme do. So ask which one applies. Either answer is fine. Neither is not.

Does TrustMark Matter for a Heat Pump Installation?

TrustMark is useful but not essential for a heat pump paid for privately or through the Boiler Upgrade Scheme, because Ofgem’s installer guidance for that scheme asks for MCS certification and consumer protection rather than TrustMark registration. TrustMark does matter for energy company funded work such as ECO4, where installers must be TrustMark registered. RECC is also a TrustMark Scheme Operator, so you will often see the logo on RECC members’ paperwork.

Do Manufacturer Accreditations Make a Difference?

Manufacturer accreditation mainly affects your warranty, because many brands give longer cover when a trained, approved installer fits and registers the unit. Mitsubishi Electric, for example, advertises Ecodan warranties of up to 3 years through standard installers, up to 5 years through accredited installers and up to 7 years through its Business Solutions Partners, subject to terms. Ask which warranty length applies to your quote, who registers it and what servicing it needs to stay valid.

What Should a Proper Heat Pump Survey Include?

A proper survey includes a room-by-room heat loss calculation to BS EN 12831-1:2017, which is the method the MCS heat pump design standard (MIS 3005-D) requires for sizing. That means someone measuring every heated room and recording what the walls, floors, roof and windows are made of and how well they are insulated.

The surveyor should also:

• Use the design outdoor temperature for your location and agreed target temperatures for each room.
• Check every radiator against its room’s heat loss at the proposed flow temperature.
• Ask how much hot water your household uses and where a cylinder could go.
• Look at where the outdoor unit would sit, including noise, drainage and access for servicing.
• Check your electrical supply, consumer unit and main fuse.

This takes time. A surveyor who leaves after twenty minutes without a tape measure has not done a heat loss survey. Sizing maths has its own guide on our site; the point here is that the survey must happen and you must see the numbers.

What Must a Good Heat Pump Quote Contain?

A good quote is written, itemised and comes with an MCS 031 performance estimate showing the expected efficiency and running cost for your home. MCS installers must give this estimate at the quoting stage, and because it uses a standard method you can compare estimates from different MCS installers.

After the full design is done, the design standard also requires the installer to give you the room-by-room heat losses, hot water demand, emitter sizes, the design flow temperature and the expected seasonal efficiency before work starts. If a company is reluctant to share these, treat that as a warning.

What Questions Should I Ask a Heat Pump Installer?

Ask questions that make the installer show their working, starting with how they calculated your home’s heat loss and what flow temperature they have designed for.

1. Are you MCS certified for heat pumps, and what is your certification number?
2. Are you on the redeveloped MCS scheme, or a member of RECC or HIES?
3. What is my home’s heat loss in kW, and can I see the room-by-room figures?
4. What flow temperature have you designed for, and which radiators need changing?
5. Will your own engineers do the work, or subcontractors?
6. Who registers the manufacturer’s warranty, and what servicing keeps it valid?
7. What happens if a room does not reach temperature in the first winter?
8. Can I speak to a couple of recent customers with a similar house?

What Are the Red Flags When Choosing a Heat Pump Installer?

The biggest red flag is a quote with no heat loss calculation behind it, because the heat pump has then been sized by guesswork. Sizing a heat pump from your existing boiler is the same mistake in a different form. A combi boiler’s output is set by instant hot water demand, so a 30kW combi tells you nothing about the heat your house loses on a cold day.

How Much Deposit Should I Pay for a Heat Pump?

Pay no more than 25% of the contract price up front, which is RECC’s standing advice, and only once you have written confirmation that the deposit is protected. RECC members must insure deposits, stage payments and the workmanship warranties they issue. HIES registers each job for deposit and stage payment protection and issues certificates to the customer.

Under the redeveloped MCS scheme, every installer must buy an MCS-approved financial protection product for each customer. MCS says it must give at least six years of cover from installation, with the excess capped at £250. It covers you if the installer goes bust, retires, refuses to fix a problem, or if the design fails.

Always pay the named company, not an individual. HIES states that payments must go directly to the named installer for its insurance-backed guarantee to be valid. And if you sign a contract at home or online, the Consumer Contracts Regulations 2013 normally give you 14 days to cancel.

How Do I Compare Heat Pump Quotes Fairly?

Compare quotes on the design first and the price second, starting with the heat loss figure each installer calculated. RECC recommends getting at least three quotes, and it is worth doing.

If two installers arrive at very different heat losses for the same house, ask each to explain their assumptions. Then compare the design flow temperatures and the SCOP in each MCS 031 estimate. A lower flow temperature usually means more radiator changes but lower running costs. Next, check scope. One quote may include new radiators, a cylinder and electrical upgrades while another leaves them out, so the cheapest headline price is often the least complete. Finally, check the grant has been deducted, because the installer applies for the Boiler Upgrade Scheme on your behalf and must take it off the price up front.

How Do I Check an Installer’s Reviews and References?

Check reviews on independent review sites first, then ask the installer for recent customers you can phone or visit. RECC also advises verifying testimonials independently rather than trusting the ones on a company’s own website.

When you read reviews, look for comments about the first winter and how problems were handled, rather than how tidy the engineers were on install day. Read how the company replies to negative reviews. Look the company up on Companies House to see how long it has traded. A good reference is a customer with a house like yours who has lived with the system through cold weather.

What Aftercare and Warranties Should a Heat Pump Installer Offer?

You should get a manufacturer’s product warranty, a written workmanship warranty from the installer, and insurance that backs the workmanship warranty if the installer stops trading. RECC notes that insurance-backed workmanship warranties typically run from 1 to 12 years depending on the provider, and the redeveloped MCS scheme sets a six-year minimum for its financial protection.

At handover, expect a commissioning record, a walkthrough of the controls and your MCS certificate. Ask whether the installer checks in after the first cold spell and how they handle call-outs. Annual servicing is usually a warranty condition, so find out who does it and what it costs.

If something goes wrong, complain to the installer first. If that fails, MCS now acts as a single point of contact for complaints and can refer unresolved cases to a free alternative dispute resolution service run by the Furniture & Home Improvement Ombudsman, for claims up to £10,000. Customers of RECC members can use Green Homes Dispute Resolution, which took over RECC’s new complaints from 20 January 2026.

What Should I Check Before Signing With a Heat Pump Installer?

Before signing, check the installer’s MCS certification yourself and make sure the quote, survey and protection paperwork are all in writing. Use this checklist.

If you would like a full heat loss survey and an itemised quote to measure others against, our HomeKOG team covers the whole of the UK.