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 County Antrim take out the old boiler and flue and seal the wall opening as part of the job. Rear gardens and side returns in County Antrim usually offer a sensible spot for the outdoor unit, checked for airflow and neighbours. If your home still cooks on gas, we talk through whether to keep the supply or switch to an induction hob.
Who it suits
- Boilers that are old, unreliable or due for replacement
- System or regular boiler homes with an existing airing cupboard
- Households ready to give up gas entirely and drop the standing charge
- Combi owners who can find space for a hot water cylinder
Grants and rules for heat pumps in Northern Ireland
Northern Ireland does not have a dedicated heat pump grant for homeowners at present, and the Boiler Upgrade Scheme does not apply here. Heat pumps have sometimes been funded through the Northern Ireland Sustainable Energy Programme, so it is worth checking what is open when you enquire about a home in County Antrim.
There is no VAT on installing a heat pump in Northern Ireland until 31 March 2027, the same as in Great Britain. Planning and building control here follow Northern Ireland's own rules, so the survey checks the unit position against them.
Gas boiler to heat pump prices in County Antrim
Here are typical prices for replacing a gas boiler with a heat pump in County Antrim, 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 |
|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,200–£12,150 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,200–£13,100 |
| 3 bedroom semi or small detached | 6–9 kW | £11,650–£15,050 |
| 4 bedroom detached | 8–12 kW | £13,600–£17,450 |
| 5+ bedroom or larger older house | 11–16 kW | £16,000–£21,850 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning. No dedicated heat pump grant currently applies in Northern Ireland.
Towns we cover in County Antrim
We cover 11 towns in County Antrim for replacing a gas boiler with a heat pump. Each links to local guide prices and the grant position for Northern Ireland.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Belfast | BT1 | Newtownabbey | 7 h 15 min |
| Lisburn | BT27 | Belfast | 7 h 16 min |
| Newtownabbey | BT37 | Belfast | 7 h 14 min |
| Carrickfergus | BT38 | Newtownabbey | 7 h 13 min |
| Ballymena | BT42 | Antrim | 7 h 12 min |
| Antrim | BT41 | Ballyclare | 7 h 13 min |
| Larne | BT40 | Carrickfergus | 7 h 12 min |
| Ballycastle | BT54 | Ballymoney | 7 h 07 min |
| Ballyclare | BT39 | Antrim | 7 h 13 min |
| Ballymoney | BT53 | Coleraine | 7 h 09 min |
| Portrush | BT56 | Portstewart | 7 h 07 min |
Replacing a gas boiler with a heat pump questions
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.
Will my hot water run out with a heat pump?
Not if the cylinder is sized properly for your household. The survey asks how many people live in the home, how many bathrooms you have and whether you prefer baths or showers, then sizes the cylinder to suit. The heat pump reheats the cylinder on a schedule, often overnight and again during the day, and an immersion heater acts as a backup.
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.