Air source heat pump quotes: how to compare quotes like for like

What to know first

This summary shows the figures, equipment and contract terms to put side by side before choosing an air source heat pump quote.

Two quotes can show similar heat pumps and very different totals because they promise different installations. The practical answer is to compare the design basis, complete scope, predicted performance and contract before comparing the final balance.

This article mainly covers air-to-water heat pumps, which feed radiators or underfloor heating and can heat stored water. Air-to-air systems use indoor fan units, so their quotes need a different comparison.

Start with the heat-loss design, not the model name

A heat-loss calculation estimates how much heat each room loses on a cold day. It is used to size the heat pump and the “emitters” — radiators or underfloor heating.

Ask for the room figures, whole-home total, assumed indoor temperatures and local outside design temperature. Under the current MCS standard, a full air-to-water heat pump must be selected to meet at least 100% of the calculated load at the proposed flow temperature, without relying on its supplementary electric heater.

Flow temperature is the water temperature leaving the heat pump. Higher temperatures can allow smaller radiators but may use more electricity. If an MCS design proposes more than 55°C, an alternative at 55°C or below should also be provided and the energy-use difference explained.

MCS’s February 2026 quotation guidance puts the principle plainly:

Use this like-for-like heat pump quote checklist

Copy this starting-point table into a spreadsheet and give every installer the same headings. It reflects current MCS design, quotation and handover requirements and Ofgem’s rules for grant-funded quotes.

Different designs can both be valid. Ask the installer to explain, in writing, how each difference changes price, comfort, energy use or responsibility. Ofgem encourages multiple quotes partly because they reveal alternative design approaches.

Expert insight

“Compare the promised finished system, not just the outdoor unit. An apparent saving may be work moved into exclusions or “customer responsibility”.”

Giles Crosse

Energy Editor

Experienced editor, journalist and communications consultant specialising in consumer energy and low carbon technologies.

• Editor and campaign author for Shell, EDF Energy and Good Energy.
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Make the performance forecasts comparable

Seasonal coefficient of performance, or SCoP, estimates average efficiency across a year. A figure of 3 means three units of heat per unit of electricity under the calculation’s assumptions; it does not guarantee bills.

Ask for annual heat demand, SCoP, predicted electricity use and the electricity price used. Check whether pumps, controls, hot-water cycles, immersion heating and any supplementary heater are included. A much lower forecast may reflect different assumptions rather than a better system.

As a rough editorial check, heat demand divided by seasonal performance should be in the same broad range as heat-pump electricity use. This is an inference, not an official sizing method, and auxiliaries or different calculation methods can explain a gap.

Good to know

MCS requires the performance estimate and key product data before contract, but allows the full design to follow. A material design or performance change requires an updated estimate, contract variation and an opportunity to cancel without further cost.

Separate the price, grant, VAT and exclusions

Energy Saving Trust’s page, updated 16 July 2026, gives a typical air source heat pump installation cost of around £12,000. Property size, heat-pump size and radiator work can change it, so it is not a fair-price benchmark for an individual home.

In England and Wales, compare the pre-grant total, grant and balance. Checked on 11 August 2026, the standard air-to-water Boiler Upgrade Scheme grant is £7,500. A £9,000 rate applies only to qualifying off-gas properties replacing oil or liquefied petroleum gas, for applications properly made from 21 July 2026 to 31 March 2027. Ofgem decides eligibility.

Ofgem describes the expected survey stage as follows:

The grant must be an upfront discount. The contract should say what happens if the application fails or a voucher is revoked, because any later claim for the discounted amount depends on the agreed terms.

Scotland has separate support: Home Energy Scotland lists a grant and optional interest-free loan of up to £7,500 each, with a £1,500 rural grant uplift, subject to its rules. Energy Saving Trust said on 16 July 2026 that Northern Ireland had no specific household heat-pump grant.

Qualifying installed heat pumps are temporarily zero-rated for VAT until 31 March 2027, with 5% scheduled from 1 April 2027. Distinct building work can be treated differently, so ask for VAT to be itemised.

Check permissions, electrics and the contract

The quote should name who handles each approval. Planning rules vary by nation and property. Listed buildings, conservation areas, flats and leasehold homes can need extra checks or consent. MCS 020 a)’s permitted-development sound calculation tests against 37 dB at specified neighbouring positions, but passing it does not establish every planning condition.

The distribution network operator, or DNO, runs the local electricity network. In Great Britain, the installer determines whether the heat pump can be notified after fitting or needs approval first. The quote should state who handles this and any supply upgrade.

MCS guidance says the contract should cover the itemised work, equipment, timetable, permissions, extras, VAT, grant, payments, warranties, deposit and financial protection, cancellation, variations and complaints. Agreeing to a quote or paying a deposit can form a contract. Work agreed online, by phone or away from the trader’s premises normally has a 14-day cooling-off period, subject to conditions and exceptions.

At handover, expect commissioning information, maintenance requirements, manuals, warranties and an MCS certificate. Put these deliverables and servicing arrangements in the quote.

Compare the quotes in six steps

1. Householder: Give every installer the same property, heating, occupancy, hot-water and planned-insulation details.

2. Installer: Surveys the home and provides the design basis, product data, itemised scope, forecast and price.

3. Householder: Enters each answer in one sheet, using the gross price before grant.

4. Installer: Answers gaps in writing and reissues the quote if its scope changes.

5. Householder: Checks funding conditions, approvals, exclusions, payment protection and cancellation terms.

6. Both: Keep the final design, agreed variations and handover documents.

When professional input may help

Conflicting designs may justify input from an independent heating engineer or energy assessor. Ask the local authority about uncertain planning, the DNO about connection, and a freeholder or managing agent about leasehold consent.

Consumer disputes may need the installer’s consumer code, Citizens Advice or Consumerline in Northern Ireland.

Key takeaways

• Compare the complete designed system and pre-grant price, not only the model or final balance.

• Put heat loss, outside design temperature and flow temperature on one comparison sheet.

• Match emitters, cylinder, controls, electrics, siting, approvals and making-good line by line.

• Compare consumption forecasts only when their heat demand, efficiency and tariff are stated.

• Treat funding, VAT and planning as date-sensitive and conditional.

• Do not accept unresolved exclusions as fixed-price work.

Frequently asked questions