- Area
- Greater London
- Postcode district
- SE23
- Nation
- England
- Guide price
- From £10,650 inc VAT
- Survey
- Free for installation enquiries
Gas boiler to heat pump in Forest Hill: what to expect
Homes around Forest Hill range from older terraces to newer estates, and each needs a different design. That is why we survey before we quote.
Installers in Forest Hill take out the old boiler and flue and seal the wall opening as part of the job. Households across Greater London moving off gas can have a survey in Forest Hill that compares running costs on realistic assumptions.
Moving from mains gas to a heat pump means finding cylinder space, deciding what happens to the gas supply and comparing running costs on realistic assumptions.
- System or regular boiler homes with an existing airing cupboard
- Boilers that are old, unreliable or due for replacement
- Households ready to give up gas entirely and drop the standing charge
What's included
- Free survey with heat loss calculation and cylinder siting
- Commissioning, MCS certificate and grant application in England and Wales where eligible
- Removal of the gas boiler, flue and any loft tanks
- Capping of the gas pipe at the boiler position where you are giving up gas
- Heat pump cylinder, outdoor unit and weather compensation controls
If your Forest Hill home still cooks on gas, we talk through whether to keep the supply or switch to an induction hob.
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 Forest Hill quote.
There is no VAT on installing a heat pump anywhere in the UK until 31 March 2027. In England most houses can have an air source heat pump under permitted development, provided the unit meets the MCS noise and siting standards; the old 1 m boundary limit was removed on 29 May 2025. We flag listed buildings, flats and sensitive conservation-area positions at survey.
Guide prices for replacing a gas boiler with a heat pump in Forest Hill
These are guide prices for Greater London, installed and including VAT. Your final price is fixed in a written quote after the survey and depends on the heat loss of the house, the radiators that need changing and where the unit goes.
| Home | Typical size | Installed guide price | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £10,650–£14,000 | £3,150–£6,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £11,750–£15,100 | £4,250–£7,600 |
| 3 bedroom semi or small detached | 6–9 kW | £13,450–£17,350 | £5,950–£9,850 |
| 4 bedroom detached | 8–12 kW | £15,700–£20,150 | £8,200–£12,650 |
| 5+ bedroom or larger older house | 11–16 kW | £18,500–£25,200 | £11,000–£17,700 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
How long is the heating season in Forest Hill?
On the shortest day Forest Hill gets about 7 hours 50 minutes of daylight, and the winter sun reaches only around 15° above the horizon at noon. Winters this far south are milder than in most of the UK, which helps a heat pump run at low flow temperatures for much of the season.
The steps for replacing a gas boiler with a heat pump in Forest Hill
- Tell us about your home: postcode, property type and current heating.
- We book a survey in Forest Hill; the surveyor measures rooms, windows and radiators and looks at cylinder space.
- The design and quote arrive in writing, including radiator changes and the outdoor unit position.
- On installation days the old system is removed and the new one fitted and filled.
- We commission the heat pump, show you the controls and register the installation.
Replacing a gas boiler with a heat pump in Forest Hill: questions
How long does installation take in Forest Hill?
Most installations take 2–4 days on site. Jobs with several radiator changes or new pipework take longer, and your quote for a Forest Hill home states the expected time.
Can you service a heat pump in Forest Hill that someone else installed?
Yes. We arrange servicing and repairs for most air source heat pumps in Forest Hill, whoever fitted them. Tell us the make and model when you book.
Where would the outdoor unit go on a Forest Hill house?
Usually at the side or rear, on a level base with space around it for airflow and servicing, away from bedroom windows where possible. The surveyor checks positions at your Forest Hill home.
What if my gas boiler is fairly new?
A newer boiler can still be replaced, but the timing is worth weighing. Some owners switch when the boiler needs a major repair; others prefer to plan the change for a convenient time. Across the UK, heat pump installation is zero-rated for VAT until 31 March 2027. A hybrid system, which keeps the boiler alongside a heat pump, is another option, though it is not eligible for the Boiler Upgrade Scheme in England and Wales.
Can a heat pump replace a combi boiler?
Yes, but you need room for a hot water cylinder, because heat pumps store hot water rather than heating it on demand. Most homes find a space in a cupboard, utility room, garage or under the stairs, and compact or combined indoor units help where space is tight. The survey measures the options first, so you know where everything will go before you accept the quote.