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.
Houses in County Londonderry with a rear wall close to the cylinder location usually suit a monobloc unit with a short pipe run. For County Londonderry terraces with small yards, the survey confirms the unit fits with the clearances it needs. In exposed spots around County Londonderry, 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
- Owners who want the simplest installation, with no indoor refrigerant
- Homes where the unit can sit within a short pipe run of the cylinder
- Houses and bungalows with outdoor space close to where pipes enter the home
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 Londonderry is therefore shown without a grant deduction; if support becomes available we will tell you how it applies.
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 Londonderry
These are guide prices for County Londonderry, 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 Londonderry
We cover 7 towns in County Londonderry for monobloc heat pumps. Each links to local guide prices and the grant position for Northern Ireland.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Derry/Londonderry | BT48 | Limavady | 7 h 10 min |
| Coleraine | BT52 | Portstewart | 7 h 08 min |
| Dungiven | BT47 | Limavady | 7 h 11 min |
| Limavady | BT49 | Dungiven | 7 h 09 min |
| Maghera | BT46 | Magherafelt | 7 h 12 min |
| Magherafelt | BT45 | Maghera | 7 h 13 min |
| Portstewart | BT55 | Coleraine | 7 h 08 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.
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.
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.
Are monobloc heat pumps covered by grants?
Yes. Monobloc units are air-to-water heat pumps, so in England and Wales they are covered by the Boiler Upgrade Scheme grant of £7,500 for eligible homes, or £9,000 when replacing oil or LPG heating within the published dates. In Scotland, Home Energy Scotland funding requires an MCS-certified installer and products. There is no dedicated homeowner heat pump grant in Northern Ireland at present.