- Area
- Surrey
- Postcode district
- GU9
- Nation
- England
- Guide price
- From £10,150 inc VAT
- Survey
- Free for installation enquiries
Gas boiler to heat pump for Farnham homes
Most homes can run on a heat pump if the system is designed properly, and Farnham is no different. The key is matching the heat pump and radiators to the home's heat loss.
If your Farnham home still cooks on gas, we talk through whether to keep the supply or switch to an induction hob. Semi-detached and terraced houses in Farnham often have an airing cupboard that can be reused for a heat pump cylinder.
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.
- Combi owners who can find space for a hot water cylinder
- System or regular boiler homes with an existing airing cupboard
- Boilers that are old, unreliable or due for replacement
What's included
- Heat pump cylinder, outdoor unit and weather compensation controls
- Commissioning, MCS certificate and grant application in England and Wales where eligible
- Removal of the gas boiler, flue and any loft tanks
- System flush and radiator upgrades where the design calls for them
- Free survey with heat loss calculation and cylinder siting
Installers in Farnham take out the old boiler and flue and seal the wall opening as part of the job.
Grants and rules for heat pumps in England
Homes in Farnham 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.
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.
What to budget for replacing a gas boiler with a heat pump in Farnham
Guide prices for Farnham and the rest of Surrey are shown below, installed and inc VAT. We publish ranges rather than a single figure because design details move the price, and the written quote after survey fixes it.
| Home | Typical size | Installed guide price | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £10,150–£13,400 | £2,650–£5,900 |
| 2–3 bedroom terrace or semi | 5–7 kW | £11,250–£14,450 | £3,750–£6,950 |
| 3 bedroom semi or small detached | 6–9 kW | £12,850–£16,600 | £5,350–£9,100 |
| 4 bedroom detached | 8–12 kW | £15,000–£19,250 | £7,500–£11,750 |
| 5+ bedroom or larger older house | 11–16 kW | £17,650–£24,100 | £10,150–£16,600 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
How long is the heating season in Farnham?
Farnham sees roughly 7 hours 52 minutes of daylight in late December against 16 hours 35 minutes in June. Milder southern winters suit heat pumps well, though the system is still sized for a cold snap rather than an average day.
The steps for replacing a gas boiler with a heat pump in Farnham
- Tell us about your home: postcode, property type and current heating.
- We book a survey in Farnham; 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 Farnham: questions
What size heat pump does a Farnham home need?
It depends on the heat loss, not the postcode. As a rough guide, a 3 bedroom semi often needs 6–9 kW, but the room-by-room survey sets the actual size for your Farnham home.
How long does a heat pump survey take in Farnham?
A home survey in Farnham usually takes one to two hours. The surveyor measures every heated room, checks windows, walls and radiators, and looks at where the outdoor unit and cylinder can go.
Do I need new radiators for a heat pump in Farnham?
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 Farnham home gives a room-by-room list.
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.
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.