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.
Homes in Greater London 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 Greater London whoever fitted the original system, including monobloc and split units. Some of the earlier heat pumps in Greater London are now reaching the age where replacement is worth considering.
Who it suits
- Units that have failed with a major fault, such as a compressor failure
- Oversized systems that short cycle and cost more to run than expected
- Systems that were undersized and struggle in cold weather
- Older units where parts are becoming hard to source
Grants and rules for heat pumps in England
Homes in Greater London 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 Greater London
Guide prices for Greater London, 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 | £6,700–£10,650 |
| Full system replacement, 2–3 bedroom terrace or semi | £11,750–£15,100 |
| Full system replacement, 3 bedroom semi or small detached | £13,450–£17,350 |
| Full system replacement, 4 bedroom detached | £15,700–£20,150 |
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 Greater London
We cover 90 towns in Greater London for heat pump replacement. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Islington | N1 | Highbury | 7 h 49 min |
| Bexley | DA5 | Bexleyheath | 7 h 50 min |
| Barking | IG11 | Ilford | 7 h 49 min |
| Sutton | SM1 | Carshalton | 7 h 51 min |
| Croydon | CR0 | Purley | 7 h 51 min |
| Ilford | IG1 | Barking | 7 h 49 min |
| Harrow | HA1 | Pinner | 7 h 49 min |
| Tottenham | N17 | Wood Green | 7 h 49 min |
| Walthamstow | E17 | Leyton | 7 h 49 min |
| Dagenham | RM10 | Barking | 7 h 49 min |
| Romford | RM1 | Hornchurch | 7 h 49 min |
| Hayes | UB3 | Southall | 7 h 49 min |
| Wembley | HA9 | Hendon | 7 h 49 min |
| Fulham | SW6 | Putney | 7 h 50 min |
| Southall | UB1 | Hayes | 7 h 49 min |
| Putney | SW15 | Fulham | 7 h 50 min |
| Battersea | SW11 | Chelsea | 7 h 50 min |
| Purley | CR8 | Coulsdon | 7 h 51 min |
| Peckham | SE15 | Dulwich | 7 h 50 min |
| Chingford | E4 | Woodford Green | 7 h 48 min |
| Uxbridge | UB8 | Ruislip | 7 h 49 min |
| Wimbledon | SW19 | Morden | 7 h 50 min |
| Brixton | SW2 | Clapham | 7 h 50 min |
| Hounslow | TW3 | Twickenham | 7 h 50 min |
| Finchley | N3 | Hendon | 7 h 49 min |
| Mitcham | CR4 | Morden | 7 h 51 min |
| Feltham | TW13 | Hounslow | 7 h 50 min |
| Acton | W3 | Chiswick | 7 h 49 min |
| Beckenham | BR3 | Bromley | 7 h 50 min |
| Chelsea | SW3 | Battersea | 7 h 50 min |
| Streatham | SW16 | Balham | 7 h 50 min |
| Eltham | SE9 | Blackheath | 7 h 50 min |
| Morden | SM4 | Mitcham | 7 h 51 min |
| Carshalton | SM5 | Sutton | 7 h 51 min |
| Catford | SE6 | Lewisham | 7 h 50 min |
| Surbiton | KT6 | Kingston upon Thames | 7 h 51 min |
| Stratford | E15 | Leyton | 7 h 49 min |
| Chiswick | W4 | Acton | 7 h 50 min |
| Ruislip | HA4 | Pinner | 7 h 49 min |
| Greenwich | SE10 | Blackheath | 7 h 50 min |
| Barnet | EN5 | Mill Hill | 7 h 48 min |
| Wood Green | N22 | Crouch End | 7 h 49 min |
| Muswell Hill | N10 | Crouch End | 7 h 49 min |
| Highbury | N5 | Islington | 7 h 49 min |
| Coulsdon | CR5 | Purley | 7 h 51 min |
| Hornchurch | RM11 | Upminster | 7 h 49 min |
| Blackheath | SE3 | Lewisham | 7 h 50 min |
| New Malden | KT3 | Kingston upon Thames | 7 h 51 min |
| Woodford Green | IG8 | Chingford | 7 h 48 min |
| Richmond | TW9 | Twickenham | 7 h 50 min |
| Barnes | SW13 | Putney | 7 h 50 min |
| Notting Hill | W11 | Kensington | 7 h 49 min |
| Pinner | HA5 | Harrow | 7 h 49 min |
| Golders Green | NW11 | Hampstead | 7 h 49 min |
| Tooting | SW17 | Balham | 7 h 50 min |
| Chislehurst | BR7 | Sidcup | 7 h 50 min |
| Orpington | BR6 | Chislehurst | 7 h 51 min |
| Balham | SW12 | Tooting | 7 h 50 min |
| Bexleyheath | DA6 | Bexley | 7 h 50 min |
| Bromley | BR1 | Beckenham | 7 h 51 min |
| Camden | NW1 | Kentish Town | 7 h 49 min |
| Clapham | SW4 | Brixton | 7 h 50 min |
| Crouch End | N8 | Highgate | 7 h 49 min |
| Dulwich | SE21 | Brixton | 7 h 50 min |
| Ealing | W5 | Acton | 7 h 49 min |
| Edgware | HA8 | Mill Hill | 7 h 48 min |
| Enfield | EN1 | Southgate | 7 h 48 min |
| Forest Hill | SE23 | Sydenham | 7 h 50 min |
| Hackney | E8 | Stoke Newington | 7 h 49 min |
| Hammersmith | W6 | Notting Hill | 7 h 50 min |
| Hampstead | NW3 | West Hampstead | 7 h 49 min |
| Hendon | NW4 | Golders Green | 7 h 49 min |
| Highgate | N6 | Crouch End | 7 h 49 min |
| Kensington | W8 | Notting Hill | 7 h 50 min |
| Kentish Town | NW5 | Camden | 7 h 49 min |
| Kingston upon Thames | KT1 | Surbiton | 7 h 50 min |
| Lewisham | SE13 | Blackheath | 7 h 50 min |
| Leyton | E10 | Walthamstow | 7 h 49 min |
| Mill Hill | NW7 | Edgware | 7 h 48 min |
| Sidcup | DA14 | Chislehurst | 7 h 50 min |
| Southgate | N14 | Enfield | 7 h 48 min |
| Stoke Newington | N16 | Highbury | 7 h 49 min |
| Sydenham | SE26 | Forest Hill | 7 h 50 min |
| Teddington | TW11 | Twickenham | 7 h 50 min |
| Twickenham | TW1 | Teddington | 7 h 50 min |
| Upminster | RM14 | Hornchurch | 7 h 49 min |
| Wandsworth | SW18 | Putney | 7 h 50 min |
| Wanstead | E11 | Leyton | 7 h 49 min |
| West Hampstead | NW6 | Hampstead | 7 h 49 min |
| Woolwich | SE18 | Eltham | 7 h 50 min |
Heat pump replacement questions
How long does an air source heat pump last?
Air source heat pumps typically last 15–20 years, depending on the quality of the original design, how hard the unit has worked, where it is sited and how well it has been serviced. Units that short cycle or run at high flow temperatures for years may wear sooner. Annual servicing helps components last and spots problems early.
Can I replace just the outdoor unit?
Often, yes, if the rest of the system is sound and correctly designed. The cylinder, controls and radiators can stay where they are compatible with the new unit. Some older cylinders and controllers do not work with a new heat pump, and the survey checks this. If the original design was the problem, replacing only the unit will not fix it.
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.