Guide · Buying
Questions to ask a heat pump installer
Use these on every quote you receive. The answers vary more than the prices.
The most important question to ask any UK heat pump installer is whether the quote is based on a room-by-room heat loss calculation and what design flow temperature it assumes — a quote below 45°C flow with an MCS performance estimate is the strongest single indicator of a well-designed system.
We’re funded by installer referral fees when you request quotes. Our editorial coverage isn’t paid for — read our editorial policy and how we rank installers.
Design questions
- Is the sizing based on a room-by-room heat loss survey, and can I see it?
- What design flow temperature have you assumed, and at what outdoor design temperature?
- What SCOP does the MCS performance estimate show at that flow temperature?
- Which radiators need upsizing, and is that included in the price?
- Where will the outdoor unit go, and what is the predicted noise level at the nearest window?
Commercial questions
- Is the £7,500 grant already deducted from this figure?
- What is excluded — electrical upgrades, scaffolding, making good, cylinder cupboard works?
- What workmanship warranty do you provide, and who honours it if you cease trading?
- What is the payment schedule, and is any deposit protected?
- Can you provide two recent local references with the same system type?
Answers that should worry you
Sizing from floor area alone. A flow temperature of 55°C with no plan to lower it. Refusal to share the heat loss calculation. Large upfront deposits. Vague exclusions. Any of these justify getting another quote.
Frequently asked questions
- What should I ask a heat pump installer before signing?
- Ask for the room-by-room heat loss calculation, the design flow temperature, the MCS performance estimate, what is excluded, and the workmanship warranty terms.
- How many quotes should I get?
- Three is the practical minimum — design approaches and prices vary widely for identical properties.
- Is a low flow temperature always better?
- Lower flow temperature means higher efficiency, but it requires emitters big enough to deliver the heat. The design has to balance both.
- MCS Certified — Installer certification scheme required for grant eligibility.
- Energy Saving Trust — Heat pump efficiency, running cost and SCOP benchmarks (UK).
- Boiler Upgrade Scheme — GOV.UK — Official guidance on the £7,500 BUS grant in England and Wales.
Start now — it’s free
Get matched with MCS-certified installers
Up to three free, no-obligation quotes from vetted local installers. 60-second form.