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.
A survey in Gwent checks the unit position, pipe route and clearance zones together for homes across Gwent. Semi-detached homes in Gwent often have a side wall where a monobloc unit can sit on a frame, clear of the path. For Gwent terraces with small yards, the survey confirms the unit fits with the clearances it needs.
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 Wales
Homes in Gwent can use the Boiler Upgrade Scheme, which applies in Wales as well as England: £7,500 towards an air source heat pump, or £9,000 when it replaces oil or LPG heating for installations from 21 July 2026 to 31 March 2027. The MCS-certified installer named in your quote applies and deducts the grant.
Installing heat pumps is zero-rated for VAT across the UK until 31 March 2027. Wales has its own permitted development rules for air source heat pumps, so we check what applies to your property, including listed building and conservation-area constraints, at the survey.
Monobloc heat pumps prices in Gwent
Here are typical prices for monobloc heat pumps in Gwent, 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 | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,500–£12,500 | £2,000–£5,000 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,500–£13,500 | £3,000–£6,000 |
| 3 bedroom semi or small detached | 6–9 kW | £12,000–£15,500 | £4,500–£8,000 |
| 4 bedroom detached | 8–12 kW | £14,000–£18,000 | £6,500–£10,500 |
| 5+ bedroom or larger older house | 11–16 kW | £16,500–£22,500 | £9,000–£15,000 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Towns we cover in Gwent
We cover 11 towns in Gwent for monobloc heat pumps. Each links to local guide prices and the grant position for Wales.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Newport (Gwent) | NP20 | Risca | 7 h 49 min |
| Cwmbran | NP44 | Pontypool | 7 h 48 min |
| Pontypool | NP4 | Cwmbran | 7 h 47 min |
| Ebbw Vale | NP23 | Tredegar | 7 h 47 min |
| Risca | NP11 | Newport (Gwent) | 7 h 48 min |
| Blackwood | NP12 | Bargoed | 7 h 48 min |
| Abergavenny | NP7 | Crickhowell | 7 h 46 min |
| Caldicot | NP26 | Chepstow | 7 h 49 min |
| Chepstow | NP16 | Caldicot | 7 h 48 min |
| Monmouth | NP25 | Chepstow | 7 h 46 min |
| Tredegar | NP22 | Ebbw Vale | 7 h 47 min |
Monobloc heat pumps questions
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.
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.

