Replacing a gas boiler with a heat pump means removing the boiler and installing an air-to-water heat pump that heats your radiators and a stored hot water cylinder instead. Most UK homes heat with mains gas, so this is the switch many households are weighing up, and the existing radiators and pipework can often be reused with some changes. What needs most planning depends on the type of boiler you have now.
Installers in Northamptonshire take out the old boiler and flue and seal the wall opening as part of the job. Households across Northamptonshire moving off gas can have a survey in Northamptonshire that compares running costs on realistic assumptions. Many gas-heated homes in Northamptonshire have a combi boiler in the kitchen, so the survey starts by finding the right place for a cylinder.
Who it suits
- System or regular boiler homes with an existing airing cupboard
- Combi owners who can find space for a hot water cylinder
- Households ready to give up gas entirely and drop the standing charge
- Homes in England and Wales eligible for the Boiler Upgrade Scheme
Grants and rules for heat pumps in England
Homes in Northamptonshire 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.
Gas boiler to heat pump prices in Northamptonshire
These are guide prices for Northamptonshire, 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 | £9,500–£12,500 | £2,000–£5,000 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,500–£13,500 | £3,000–£6,000 |
| 3 bedroom semi or small detached | 6–9 kW | £12,000–£15,500 | £4,500–£8,000 |
| 4 bedroom detached | 8–12 kW | £14,000–£18,000 | £6,500–£10,500 |
| 5+ bedroom or larger older house | 11–16 kW | £16,500–£22,500 | £9,000–£15,000 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Towns we cover in Northamptonshire
We cover 10 towns in Northamptonshire for replacing a gas boiler with a heat pump. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Northampton | NN1 | Wellingborough | 7 h 42 min |
| Corby | NN17 | Desborough | 7 h 39 min |
| Kettering | NN16 | Desborough | 7 h 40 min |
| Wellingborough | NN8 | Rushden | 7 h 41 min |
| Rushden | NN10 | Wellingborough | 7 h 41 min |
| Daventry | NN11 | Towcester | 7 h 42 min |
| Brackley | NN13 | Towcester | 7 h 44 min |
| Desborough | LE16 | Kettering | 7 h 40 min |
| Oundle | PE8 | Corby | 7 h 39 min |
| Towcester | NN12 | Northampton | 7 h 43 min |
Replacing a gas boiler with a heat pump questions
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.
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.
Should I have my gas meter removed?
If gas is used for nothing else, removing the meter ends the gas standing charge, which is about £108 a year at the October to December 2026 price cap. If you still cook on gas or have a gas fire, you will need to keep the supply. Meter removal is arranged through your gas supplier, usually once the heat pump is running; the pipe at the boiler position is capped during the installation.
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.