If you have a combi, there is no cylinder at the moment, so the first question is where one can go. If you have a system or regular boiler, you already have a cylinder, but it is unlikely to suit a heat pump, which needs a larger internal coil to heat water at lower temperatures. Regular boilers also have tanks in the loft that can usually be taken out, freeing space.
Households across County Down moving off gas can have a survey in County Down that compares running costs on realistic assumptions. If your home still cooks on gas, we talk through whether to keep the supply or switch to an induction hob. Many gas-heated homes in County Down have a combi boiler in the kitchen, so the survey starts by finding the right place for a cylinder.
Who it suits
- Boilers that are old, unreliable or due for replacement
- 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
Grants and rules for heat pumps in Northern Ireland
The Boiler Upgrade Scheme covers England and Wales only, and there is currently no dedicated heat pump grant for homeowners in Northern Ireland. Our quote for a home in County Down is therefore shown without a grant deduction; if support becomes available we will tell you how it applies.
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 Down
These are guide prices for County Down, 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 |
|---|---|---|
| 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 Down
We cover 13 towns in County Down 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 |
|---|---|---|---|
| Bangor (County Down) | BT20 | Newtownards | 7 h 14 min |
| Newtownards | BT23 | Comber | 7 h 15 min |
| Newry | BT35 | Warrenpoint | 7 h 20 min |
| Banbridge | BT32 | Dromore | 7 h 18 min |
| Ballynahinch | BT24 | Downpatrick | 7 h 17 min |
| Comber | BT23 | Newtownards | 7 h 15 min |
| Donaghadee | BT21 | Bangor (County Down) | 7 h 14 min |
| Downpatrick | BT30 | Ballynahinch | 7 h 18 min |
| Dromore | BT25 | Banbridge | 7 h 17 min |
| Holywood | BT18 | Newtownabbey | 7 h 14 min |
| Kilkeel | BT34 | Warrenpoint | 7 h 21 min |
| Newcastle | BT33 | Downpatrick | 7 h 20 min |
| Warrenpoint | BT34 | Newry | 7 h 21 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.
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.
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.
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.

