Not every replacement is about age. Some heat pumps were sized by rule of thumb, paired with radiators that are too small or set up without weather compensation, leaving homes cold or bills high. Replacing the unit alone will not fix those problems, so we start with a fresh heat loss survey and check the radiators, pipework, cylinder and controls.
New outdoor units in Buckinghamshire may differ in size from the old one, so the base and position are checked at survey. Some of the earlier heat pumps in Buckinghamshire are now reaching the age where replacement is worth considering. Homes in Buckinghamshire with a heat pump that never kept them warm can have the whole design checked before a new unit is chosen.
Who it suits
- Oversized systems that short cycle and cost more to run than expected
- Units that have failed with a major fault, such as a compressor failure
- Older units where parts are becoming hard to source
- Heat pumps nearing the end of their typical life with rising repair costs
Grants and rules for heat pumps in England
Homes in Buckinghamshire can use the Boiler Upgrade Scheme, which takes £7,500 off the cost of an air source heat pump when it replaces fossil-fuel or electric heating. Replacing oil or LPG heating qualifies for £9,000 for installations from 21 July 2026 to 31 March 2027, and air-to-air systems for £2,500. The MCS-certified installer named in your quote applies for the grant and deducts it from the price.
Heat pump replacement prices in Buckinghamshire
These are guide prices including VAT. The rate for your visit in Buckinghamshire is confirmed before we book it, and any repair is priced in writing before parts are ordered.
| Work | Installed guide price |
|---|---|
| Replacing an old outdoor unit like-for-like | £6,300–£10,000 |
| Full system replacement, 2–3 bedroom terrace or semi | £11,050–£14,200 |
| Full system replacement, 3 bedroom semi or small detached | £12,600–£16,300 |
| Full system replacement, 4 bedroom detached | £14,700–£18,900 |
Installed, inc VAT. Grant funding rarely applies to replacing a heat pump, so these prices are shown without any deduction; we check eligibility at survey.
Towns we cover in Buckinghamshire
We cover 13 towns in Buckinghamshire for heat pump replacement. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Milton Keynes | MK9 | Bletchley | 7 h 44 min |
| High Wycombe | HP11 | Marlow | 7 h 48 min |
| Aylesbury | HP20 | Princes Risborough | 7 h 46 min |
| Bletchley | MK2 | Milton Keynes | 7 h 44 min |
| Amersham | HP7 | Chesham | 7 h 48 min |
| Chesham | HP5 | Amersham | 7 h 48 min |
| Gerrards Cross | SL9 | Chalfont St Peter | 7 h 49 min |
| Chalfont St Peter | SL9 | Gerrards Cross | 7 h 48 min |
| Marlow | SL7 | High Wycombe | 7 h 49 min |
| Beaconsfield | HP9 | Chalfont St Peter | 7 h 48 min |
| Buckingham | MK18 | Brackley | 7 h 44 min |
| Olney | MK46 | Milton Keynes | 7 h 43 min |
| Princes Risborough | HP27 | Aylesbury | 7 h 47 min |
Heat pump replacement questions
Will a new heat pump fit where the old one was?
Sometimes. A new unit may be a different size, weight or shape and may have different clearance requirements, so the existing base and position are checked at survey. The MCS noise assessment is carried out for the new unit, and a different position may be suggested if it improves performance or reduces sound at neighbouring windows.
Can I get a grant to replace my heat pump?
Usually not. In England and Wales, the Boiler Upgrade Scheme cannot normally fund a home that has already been funded for a heat pump, and it is aimed at replacing fossil-fuel or electric heating. Your circumstances may differ, so we check eligibility before quoting. In Scotland, check Home Energy Scotland's criteria. Northern Ireland has no dedicated grant at present.
What happens to my old heat pump?
The old outdoor unit is removed and disposed of responsibly. Its refrigerant is recovered first, which must be done by an F-gas certified engineer, and metals and components are recycled where facilities allow. If the old cylinder or controls are replaced too, they are removed at the same time, and pipework that is no longer needed is capped or taken out.
How much does it cost to replace a heat pump?
Replacing an old outdoor unit like-for-like has a guide price of £6,000–£9,500, installed and including VAT. Re-sizing, a new cylinder, radiator upgrades or new controls add to that, and each is itemised in your written quote. The final price is fixed after a survey, once we know what the existing system needs.