A split system heat pump is an air-to-water heat pump in two parts: an outdoor unit that collects heat from the air, and an indoor unit called a hydrobox where that heat is passed into the water for your heating and hot water. The two are connected by insulated refrigerant pipes rather than water pipes, so there is no water outside to freeze.
Owners across Gwent can compare split and monobloc designs side by side at a survey in Gwent. Flats and terraces in Gwent with a small yard or flat roof can suit a compact split outdoor unit. In Gwent homes where the clearest unit position is away from the plant cupboard, a split system allows a longer route indoors.
Who it suits
- Small yards, roofs or balconies that suit a more compact outdoor unit
- Homes where the outdoor unit must sit some distance from the plant space
- Exposed or frost-prone sites where outdoor water pipes would be a risk
- Owners who would rather not use glycol or anti-freeze valves
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.
There is no VAT on installing a heat pump anywhere in the UK, Wales included, until 31 March 2027. Planning rules for heat pumps in Wales are set by the Welsh Government and differ from England's, so the surveyor checks the unit position against them.
Split system heat pumps prices in Gwent
These are guide prices for Gwent, 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 | 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 split system 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 |
Split system heat pumps questions
Is a split system more efficient than a monobloc?
Not inherently. Efficiency depends far more on design, meaning correct sizing, low flow temperatures and good controls, than on whether the unit is split or monobloc. A split system can avoid the heat loss and glycol of a long outdoor water run, which helps in certain layouts. The survey estimates seasonal efficiency for the specific units proposed, so you can compare like for like.
How far apart can the outdoor unit and hydrobox be?
It depends on the model: each manufacturer sets a maximum refrigerant pipe length and height difference, and longer runs may need extra refrigerant. In practice a split system allows more flexibility than a monobloc's water pipes, so the outdoor unit can often sit on the far side of a house, on a flat roof or round a corner. The survey measures the actual route.
Do I need an F-gas engineer for a split heat pump?
Yes. Split systems usually use a fluorinated refrigerant such as R32, so installing, servicing or repairing the refrigerant circuit must by law be done by an F-gas certified engineer. That covers joining the refrigerant pipes, testing them for leaks and charging the system. Your quote sets out who carries out each part of the installation, including the refrigerant work.
Can a split system replace my combi boiler?
Yes, but like any air-to-water heat pump it needs a hot water cylinder, because it does not heat water instantly. The hydrobox can sometimes go where the combi was, with the cylinder in a cupboard, utility room or garage. Integrated units combining both are useful where one larger space is available. The survey checks what fits before the design is finalised.