Start with one brief for every installer
A cheap quote and an expensive quote may describe different jobs. One might include radiator changes, cylinder work, an electrical upgrade and making good; another may leave several of those items as allowances or exclusions. Give each installer the same description of the property, occupancy, hot-water needs and rooms that are difficult to heat.
Citizens Advice recommends getting written quotations from at least three contractors where practical. For a heat pump, consistency matters as much as the number of quotes: ask each installer to show what survey and design information will be produced, what is included and which costs can still change.
Use the same evidence pack for every visit: recent energy use, floor plans if available, radiator dimensions, photos of the current plant and any known electrical or insulation work.
Compare the design before the equipment
Heat-pump performance depends on the home and the temperatures at which the system is designed to operate. MCS design guidance covers assessment of building heat loss, selection of heat emitters and the design of the heat-pump system. Ask for the assumptions in writing rather than accepting only a model name and output rating.
The most useful comparison is whether each proposal starts from a room-by-room heat-loss assessment and explains the outdoor design condition, proposed flow temperature, emitter changes and hot-water approach. Materially different assumptions should be resolved before you compare price or projected running costs.
- Room-by-room heat-loss figures and the temperatures used in the calculation.
- Proposed heat-pump make, model and capacity, plus why it suits the design load.
- Design flow temperature and the radiators, underfloor heating or other emitters required in each room.
- Hot-water cylinder size, reheating approach and any immersion-heater provision.
- Any insulation, ventilation or fabric assumptions that the design depends on.
Build a like-for-like scope table
Copy the main scope items into a table and mark each one included, excluded, provisional or unclear. Do not treat an omission as included. Ask the installer to revise the written quote when a verbal answer changes the scope.
| Area | What the quote should make clear | Why it changes the comparison |
|---|---|---|
| Survey and design | Heat loss, design temperatures, emitter schedule and controls | Different assumptions can change system size and performance |
| Outdoor unit | Model, location, base, clearances, drainage and noise considerations | Siting and groundwork may be substantial parts of the job |
| Indoor work | Cylinder, buffer or volumiser if used, pumps, pipework and insulation | A model number alone does not describe the complete system |
| Emitters | Every radiator or underfloor-heating change and who makes good | Omitted room work can become a large extra |
| Electrical | New circuits, isolation, consumer-unit or supply work and responsibility | Some upgrades need separate assessment or pricing |
| Removal and finish | Old equipment, waste, penetrations, decoration and reinstatement | These are common boundaries between included work and extras |
| Handover | Commissioning records, controls training, documents and warranty registration | The installation is not complete when the equipment merely switches on |
Check certification, protection and grant wording
Use the official MCS search and the government installer finder to check the business rather than relying on a logo in a brochure. Ask which consumer code and deposit or workmanship protection applies, who holds the installation contract and how complaints are handled.
For the Boiler Upgrade Scheme, the installer applies on the property owner's behalf and the owner is contacted to confirm consent. Treat any grant figure as conditional until the installer has checked the property and the scheme requirements. The quote should distinguish the full contract price from the proposed grant contribution and the amount you would pay.
- Business identity, MCS certification details and the named contracting party.
- Deposit amount, protection arrangements, staged payments and cancellation terms.
- Full price, VAT, grant treatment and what happens if an application is not approved.
- Product, workmanship and performance-related warranties, with the provider and duration named.
Treat forecasts as assumptions, not promises
A running-cost forecast depends on heat demand, seasonal efficiency, electricity tariffs, control settings and household behaviour. Ask the installer to show the inputs and keep the forecast separate from the contract price. Two forecasts cannot be compared if one assumes a different indoor temperature, hot-water demand or tariff.
Ask what will be measured or checked at commissioning and what support is available if rooms do not reach the agreed design temperature. A clear handover should explain controls, maintenance, frost protection and how to report a fault.
Resolve gaps before choosing a quote
A missing item is a question, not proof of a poor installer. Send one written clarification list to each bidder and keep the replies with the quotation. Compare the revised documents only after essential assumptions and exclusions are visible.
Our quote checklist gives each written proposal the same 100-point paperwork check. It does not certify workmanship or rank installers; it helps expose gaps that need an answer before you sign.
- Why do the heat-loss results or proposed capacities differ?
- Which radiator, cylinder, electrical and making-good costs are fixed?
- Which figures are allowances, and how will a change be authorised?
- Who is responsible for permissions, network notifications and scheme paperwork?
- What evidence, certificates, manuals and warranty confirmations will be supplied at handover?
Common questions
Questions this guide should answer
What should a heat-pump quote include?
It should identify the system and contracting business, explain the survey and design basis, list the included equipment and home alterations, state exclusions and provisional sums, show the full price and payment terms, and document commissioning, warranties and aftercare.
Should I choose the cheapest heat-pump quote?
Not until the design basis and scope are comparable. A lower price may exclude emitters, electrical work, cylinder changes, making good or protection that another installer included.
Do I need three heat-pump quotes?
Three written quotes are a useful consumer benchmark where practical, but quality and consistency matter. Give each installer the same brief and resolve differences in assumptions before comparing totals.
Who applies for the Boiler Upgrade Scheme grant?
The installer applies on the property owner's behalf. The owner is contacted to confirm consent, and eligibility should be checked against the current official scheme rules.
Sources and review trail
We favour primary public guidance and link to the exact source so you can inspect it yourself.