Because the refrigerant circuit is sealed at the factory, the installer does not need to handle refrigerant on site in a typical installation, which keeps the job simpler. Inside, you still have a cylinder, controls and a small set of components for the water circuit, such as pumps, valves and an expansion vessel, but there is no indoor refrigerant unit to find wall space for.
Bungalows in County Down often let the unit sit right beside the plant cupboard, keeping water pipes short. For County Down terraces with small yards, the survey confirms the unit fits with the clearances it needs. In exposed spots around County Down, frost protection for the outdoor pipework is chosen with the site in mind.
Who it suits
- Households that want to keep refrigerant work out of routine servicing
- Houses and bungalows with outdoor space close to where pipes enter the home
- 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 Down.
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 Down
Here are typical prices for monobloc heat pumps in County Down, 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 Down
We cover 13 towns in County Down for monobloc heat pumps. 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 |
Monobloc heat pumps questions
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.
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.
What refrigerant do monobloc heat pumps use?
Most use R32 or R290. R290 is propane, a natural refrigerant with a very low global warming impact, and some models use it to reach higher flow temperatures. Because R290 is flammable, manufacturers set clearance zones around the unit from openings such as windows, doors and drains, which the survey takes into account when choosing a position.
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.

