The trade-off is that the pipes between the outdoor unit and the house carry water, so they must be protected from freezing. That is done with glycol (an anti-freeze) in the system or with anti-freeze valves that release water from the outdoor pipework if it nears freezing, for example during a power cut in cold weather. Keeping the outdoor pipe run short and well insulated also helps efficiency.
Semi-detached homes in County Antrim often have a side wall where a monobloc unit can sit on a frame, clear of the path. A survey in County Antrim checks the unit position, pipe route and clearance zones together for homes across County Antrim. Bungalows in County Antrim often let the unit sit right beside the plant cupboard, keeping water pipes short.
Who it suits
- Houses and bungalows with outdoor space close to where pipes enter the home
- Households that want to keep refrigerant work out of routine servicing
- Owners who want the simplest installation, with no indoor refrigerant
- Homes where the unit can sit within a short pipe run of the 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.
Installing heat pumps has been zero-rated for VAT in Northern Ireland since 1 May 2023, in line with the rest of the UK, until 31 March 2027. Northern Ireland has its own permitted development rules and building regulations, and we confirm what applies to your property at survey.
Monobloc heat pumps prices in County Antrim
These are guide prices for County Antrim, 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 Antrim
We cover 11 towns in County Antrim for monobloc heat pumps. 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 |
Monobloc heat pumps questions
Do monobloc heat pumps need an F-gas engineer?
For a typical installation no refrigerant work is needed on site, because the refrigerant circuit is sealed in the outdoor unit at the factory. That is one reason monobloc installs are simpler. If the sealed circuit ever develops a fault or leak, any repair to it must be done by an F-gas certified engineer, as with every refrigerant system.
Is glycol or anti-freeze valves the better option?
Neither is right for every home. Glycol gives reliable frost protection without draining but slightly reduces efficiency and needs its concentration checked at servicing. Anti-freeze valves keep the system water plain but release water if pipes near freezing during a power cut, so the system then needs refilling. The installer recommends one based on the unit, pipe run and how exposed the site is.
What is the difference between monobloc and split heat pumps?
A monobloc unit holds all of its refrigerant in the outdoor unit and sends heated water into the house. A split system has an outdoor unit and an indoor unit called a hydrobox, connected by refrigerant pipes, with heat passed to water indoors. Monobloc installs are simpler; splits avoid outdoor water pipes but need an F-gas certified engineer for the refrigerant work. Our monobloc vs split guide compares them.
How far can a monobloc unit be from the house?
Usually as close as practical, because water pipes outside lose heat and need frost protection. Manufacturers set limits on pipe length and size, and longer runs need larger, better-insulated pipes. Most homes site the unit against or near an outside wall close to where the pipes enter. If the only good position is far from the house, a split system may suit better.