- Area
- Greater London
- Postcode district
- SE13
- Nation
- England
- Guide price
- From £10,650 inc VAT
- Survey
- Free for installation enquiries
What to know about replacing a gas boiler with a heat pump in Lewisham
Homes around Lewisham range from older terraces to newer estates, and each needs a different design. That is why we survey before we quote.
Many gas-heated homes in Lewisham have a combi boiler in the kitchen, so the survey starts by finding the right place for a cylinder. If your Lewisham home still cooks on gas, we talk through whether to keep the supply or switch to an induction hob.
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.
- Boilers that are old, unreliable or due for replacement
- Households ready to give up gas entirely and drop the standing charge
- Homes in England and Wales eligible for the Boiler Upgrade Scheme
What's included
- Free survey with heat loss calculation and cylinder siting
- System flush and radiator upgrades where the design calls for them
- Removal of the gas boiler, flue and any loft tanks
- Heat pump cylinder, outdoor unit and weather compensation controls
- Commissioning, MCS certificate and grant application in England and Wales where eligible
Rear gardens and side returns in Lewisham usually offer a sensible spot for the outdoor unit, checked for airflow and neighbours.
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 Lewisham quote.
Installing heat pumps is zero-rated for VAT across the UK until 31 March 2027. Since 29 May 2025, permitted development in England allows up to two air source heat pumps on a house, each up to 1.5 m³, with no blanket 1 m boundary rule — the installation must still meet the MCS planning standards, including the noise check. Listed buildings, flats and some conservation-area positions need extra consent, which we check at survey.
Guide prices for replacing a gas boiler with a heat pump in Lewisham
Here are typical prices for replacing a gas boiler with a heat pump in Greater London, installed and including VAT. Use the guide price tool for a figure based on your home, then a survey confirms it in writing.
| 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.
Short winter days in Lewisham and what they mean
On the shortest day Lewisham 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.
What happens after you enquire in Lewisham?
- Start online with a guide price or call us.
- A home survey in Lewisham gives us the room-by-room heat loss.
- Your written quote sets out the design, the price and the grant position where you live.
- Installation is booked for dates that suit you; most homes take 2–4 days on site.
- After commissioning you get a handover of the controls and settings, plus the certificates.
Replacing a gas boiler with a heat pump in Lewisham: questions
Do I need new radiators for a heat pump in Lewisham?
Often some, not all. Heat pumps run best at lower water temperatures, so rooms with small radiators may need larger ones. The survey of your Lewisham home gives a room-by-room list.
Do you cover Blackheath as well as Lewisham?
Yes. We arrange surveys and installation in Blackheath, which is about a mile north-east of Lewisham, and across Greater London.
Where would the outdoor unit go on a Lewisham 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 Lewisham home.
Do I need to replace the cylinder I already have?
Usually, yes. Older cylinders have a small internal coil designed for water from a boiler at around 60–70°C, and they cannot take in heat quickly enough at the lower temperatures a heat pump runs at. A heat pump cylinder has a larger coil. On its own, a cylinder supplied and fitted has a guide price of £1,200–£2,200, installed and including VAT, though it is normally part of the full system price.
Is there a grant to replace a gas boiler with a heat pump?
In England and Wales, the Boiler Upgrade Scheme gives £7,500 towards an air-to-water heat pump that replaces a gas boiler, for eligible owners of existing homes. The MCS-certified installer applies to Ofgem and deducts the grant from your quote, and Ofgem contacts you to confirm. Scotland has separate Home Energy Scotland funding, and Northern Ireland has no dedicated homeowner grant at present.