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.
Across Hertfordshire and Hertfordshire, old units are removed with their refrigerant recovered by an F-gas certified engineer. Homes in Hertfordshire with a heat pump that never kept them warm can have the whole design checked before a new unit is chosen. We replace heat pumps in Hertfordshire whoever fitted the original system, including monobloc and split units.
Who it suits
- Oversized systems that short cycle and cost more to run than expected
- Systems that were undersized and struggle in cold weather
- Heat pumps nearing the end of their typical life with rising repair costs
- Older units where parts are becoming hard to source
Grants and rules for heat pumps in England
In England the Boiler Upgrade Scheme gives £7,500 towards an air source heat pump (£9,000 if it replaces oil or LPG, from 21 July 2026 to 31 March 2027), and since 28 April 2026 a valid EPC is no longer needed. The grant is applied for by the MCS-certified installer and shown as a deduction on your quote.
Heat pump replacement prices in Hertfordshire
Guide prices for Hertfordshire, including VAT. We agree the visit rate before anyone attends, so there are no surprises on the day.
| 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 Hertfordshire
We cover 17 towns in Hertfordshire for heat pump replacement. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Hemel Hempstead | HP2 | Berkhamsted | 7 h 47 min |
| Stevenage | SG1 | Hitchin | 7 h 45 min |
| St Albans | AL1 | Radlett | 7 h 47 min |
| Welwyn Garden City | AL8 | Hatfield | 7 h 46 min |
| Cheshunt | EN8 | Hoddesdon | 7 h 47 min |
| Hatfield | AL10 | Welwyn Garden City | 7 h 47 min |
| Bishop's Stortford | CM23 | Ware | 7 h 46 min |
| Hitchin | SG6 | Letchworth Garden City | 7 h 45 min |
| Hoddesdon | EN11 | Ware | 7 h 47 min |
| Letchworth Garden City | SG6 | Hitchin | 7 h 45 min |
| Harpenden | AL5 | St Albans | 7 h 46 min |
| Hertford | SG13 | Ware | 7 h 47 min |
| Berkhamsted | HP4 | Tring | 7 h 47 min |
| Ware | SG12 | Hertford | 7 h 46 min |
| Royston | SG7 | Letchworth Garden City | 7 h 44 min |
| Radlett | WD7 | St Albans | 7 h 48 min |
| Tring | HP23 | Berkhamsted | 7 h 47 min |
Heat pump replacement questions
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.
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.