How to compare heat-pump quotes without comparing price alone

Two heat-pump quotes can show similar headline prices while describing materially different systems, assumptions and included work. The useful comparison is not “which number is lower?” but “what evidence supports each proposal, what is actually included, and what is still unknown?”

1. Put every quote on the same scope

A cheaper quote is not necessarily better value if it leaves out work another installer has included. Start by identifying the common scope: heat pump model, hot-water cylinder where relevant, controls, emitters or radiator changes, electrical work, groundworks or mounting, system flushing, commissioning, disposal of existing equipment and any making-good.

Write down anything described as provisional, optional, subject to survey or excluded. Those items are where apparent price differences often reappear later.

2. Look for the design evidence behind the equipment choice

Nominal heat-pump output in kW is not, by itself, proof that a system is correctly designed for a home. A useful quotation should connect the proposed equipment to design information such as a room-by-room heat-loss calculation, design temperatures and the operating assumptions used.

If a quote does not contain this information, that does not automatically make it wrong. It does mean the evidence is incomplete and worth clarifying before commitment.

3. Compare the proposed system, not just the heat-pump brand

The outdoor unit is only part of the installation. Compare cylinder specification, controls, pumps, buffers or volumisers where proposed, valves, filters, pipework changes and emitter upgrades. Check whether the installer has described why those components are needed rather than treating a longer equipment list as automatically better.

4. Separate confirmed items from assumptions

Good quote comparison distinguishes facts from assumptions. For example, “existing consumer unit suitable” may be an assumption pending electrical inspection. “No radiator changes required” may depend on a heat-loss calculation and design flow temperature that is not attached. “Grant deducted” may rely on scheme and property conditions that need separate confirmation.

Mark each important item as confirmed, assumed, excluded or unclear. That simple classification often reveals more than comparing totals.

5. Compare price only after normalising the scope

Once the technical and work scope is aligned, compare:

• gross price before any incentive or grant assumptions;
• what the customer is expected to pay;
• optional and provisional items;
• payment stages and deposits;
• warranty and aftercare included in the price;
• work that could trigger additional charges after survey.

A useful question for each installer is: “What reasonably foreseeable work is not included in this price?”

6. Ask for missing evidence in writing

Before choosing between close quotes, send the same clarification questions to each installer. Typical questions include:

• Please provide the room-by-room heat-loss calculation and design assumptions.
• What design flow temperature has been assumed?
• Please confirm the emitter schedule and outputs at that flow temperature.
• Please confirm any electrical upgrades included or excluded.
• Please list all provisional sums, exclusions and items that could change the final price.
• Which commissioning and handover records will be supplied before final payment?

7. Be cautious with claims that need a separate decision

Installer statements about system sizing, expected performance, certification or grant eligibility should not be treated as independently verified merely because they appear in a quote. Home Quote Check can help identify whether supporting evidence is present, but it does not certify a design, approve an installer or determine eligibility for a government scheme.

A practical way to compare two or three quotes

For each quote, record the total price, system components, design evidence supplied, exclusions, unresolved questions and any assumptions. Then compare the gaps rather than awarding a simplistic score to the installer. Often the next best action is not “choose quote A” but “ask both installers the same three questions and compare the quality of the answers.”

Home Quote Check provides evidence-based decision support. It is not a substitute for site survey, competent system design, installer due diligence or professional advice where required.