How to choose a heat pump installer
Picking the right installer matters more than picking the right heat pump model. A good installer correctly sizes the system, gets your radiators flowing at the right temperature, and stands behind the install for a decade. A bad one leaves you with cold rooms and high running costs.
The seven questions to ask
1. Are you MCS-certified for the technology I want?
MCS certification is technology-specific. An installer can be MCS-certified for solar PV but not for heat pumps — those are different scope codes. Ask for their MCS number and verify it on mcscertified.com. Every installer in our directory is MCS-certified for at least one heat pump technology.
2. Are you registered for the Boiler Upgrade Scheme?
BUS registration is separate from MCS certification. Only BUS-registered installers can deduct the £7,500 grant from your bill. If they're not registered and tell you to "claim it back yourself", they're wrong — BUS only pays installers.
3. Will you do a full MCS heat-loss survey before quoting?
This is the litmus test. A proper survey takes 2–4 hours, room by room, measuring radiator outputs and U-values. An installer who quotes a kW size based on house size alone is guessing. Bad sizing is the single biggest cause of unhappy heat pump owners.
4. What flow temperature have you designed for?
A good installer will design for the lowest flow temperature your radiators allow, ideally 35–45 °C. Anything above 55 °C means either inadequate radiators or undersized pipework, and the SCOP (efficiency) drops fast. If they don't have an answer, push back.
5. What's the SCOP and how was it calculated?
SCOP (Seasonal Coefficient of Performance) is the heat pump's real-world efficiency over a year, not the manufacturer's lab figure. A competent installer should quote a SCOP for your specific design, somewhere in the 3.0–4.5 range. Treat anything above 5.0 with scepticism.
6. What's included, and what's an "extra"?
Ask for a line-item quote: heat pump, cylinder, buffer, controls, radiators, electrical, labour, commissioning, MCS paperwork. Common "extras" that surface later: new consumer unit, additional radiator upgrades, scaffolding, condensate drain. Get these in writing.
7. What happens if it doesn't perform?
A good installer will commit, in writing, to a flow temperature design target. Ask: "If after a full winter the system can't keep the house at 21 °C on a design day, what do you do?" The answer should be specific — adjust controls, replace radiators at no extra cost, or a clear remediation route. Vague answers are a red flag.
Red flags: walk away if you see these
- Quote without a survey. "Email us your details and we'll send a quote" usually means they're guessing the size.
- Pressure to sign today. Heat pumps are a 15–20 year investment. There's no legitimate reason to rush.
- Deposits before the BUS voucher is issued. Ofgem will reject claims where the installer took deposits too early.
- "You don't need to upgrade any radiators." Statistically unlikely. Most retrofits need at least one or two radiator changes.
- Doorstep selling or cold-call leads. The best installers are quietly booked out via word-of-mouth.
- Headline price much cheaper than competitors. Either they're missing something, or the cost will appear later as "extras".
Comparing quotes side by side
When you have three quotes, lay them out:
| Item | Quote A | Quote B | Quote C |
|---|---|---|---|
| Heat pump model and kW | |||
| Designed flow temperature | |||
| Predicted SCOP | |||
| Cylinder size and brand | |||
| Radiator changes included | |||
| Electrical works included | |||
| Gross price | |||
| BUS deduction | |||
| Net to you | |||
| Workmanship warranty (years) |
What the contract should say
- Designed flow temperature and the rooms that must hit a target temperature.
- Heat-loss figures and the property's design day temperature.
- The MCS scope code and the installer's MCS number.
- BUS grant amount, voucher reference, and the gross-minus-grant pricing structure.
- Manufacturer warranty length and what installer-side warranty covers.
- Commissioning and handover deliverables: MCS certificate, manufacturer commissioning report, weather-compensation settings.
- A cancellation right (you have 14 days under Consumer Contracts Regulations for off-premises contracts).
Find your three installers. Start with our regional directory and shortlist installers that operate in your region. Cross-check each one against the public MCS register at mcscertified.com.