Because the refrigerant pipes are joined and charged on site, and split systems usually use a fluorinated refrigerant such as R32, the refrigerant work must by law be done by an F-gas certified engineer. That makes installation a little more involved than a monobloc, and any later repair to the refrigerant circuit also needs F-gas certified work. In return, a split system copes better with long or awkward routes between the outdoor unit and the house, within the limits the manufacturer sets.
Owners across Oxfordshire can compare split and monobloc designs side by side at a survey in Oxfordshire. Flats and terraces in Oxfordshire with a small yard or flat roof can suit a compact split outdoor unit. Installers covering Oxfordshire keep refrigerant routes neat and protected along the outside wall.
Who it suits
- Exposed or frost-prone sites where outdoor water pipes would be a risk
- Homes where the outdoor unit must sit some distance from the plant space
- Houses with indoor wall space for a boiler-sized hydrobox
- Small yards, roofs or balconies that suit a more compact outdoor unit
Grants and rules for heat pumps in England
Homes in Oxfordshire can use the Boiler Upgrade Scheme, which takes £7,500 off the cost of an air source heat pump when it replaces fossil-fuel or electric heating. Replacing oil or LPG heating qualifies for £9,000 for installations from 21 July 2026 to 31 March 2027, and air-to-air systems for £2,500. The MCS-certified installer named in your quote applies for the grant and deducts it from the price.
There is no VAT on installing a heat pump anywhere in the UK until 31 March 2027. In England most houses can have an air source heat pump under permitted development, provided the unit meets the MCS noise and siting standards; the old 1 m boundary limit was removed on 29 May 2025. We flag listed buildings, flats and sensitive conservation-area positions at survey.
Split system heat pumps prices in Oxfordshire
The ranges below are typical installed prices for homes in Oxfordshire, including VAT. A survey sets the exact figure, because two similar-looking houses in Oxfordshire can need quite different radiators and pipework.
| Home | Typical size | Installed guide price | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,900–£13,000 | £2,400–£5,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,900–£14,050 | £3,400–£6,550 |
| 3 bedroom semi or small detached | 6–9 kW | £12,500–£16,100 | £5,000–£8,600 |
| 4 bedroom detached | 8–12 kW | £14,550–£18,700 | £7,050–£11,200 |
| 5+ bedroom or larger older house | 11–16 kW | £17,150–£23,400 | £9,650–£15,900 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Towns we cover in Oxfordshire
We cover 11 towns in Oxfordshire for split system heat pumps. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Oxford | OX1 | Abingdon | 7 h 47 min |
| Banbury | OX16 | Brackley | 7 h 44 min |
| Abingdon | OX14 | Didcot | 7 h 48 min |
| Bicester | OX26 | Oxford | 7 h 45 min |
| Didcot | OX11 | Abingdon | 7 h 48 min |
| Witney | OX28 | Oxford | 7 h 47 min |
| Chipping Norton | OX7 | Stow-on-the-Wold | 7 h 45 min |
| Henley-on-Thames | RG9 | Marlow | 7 h 49 min |
| Thame | OX9 | Princes Risborough | 7 h 47 min |
| Wallingford | OX10 | Didcot | 7 h 49 min |
| Wantage | OX12 | Didcot | 7 h 49 min |
Split system heat pumps questions
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.
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.
Is a split system eligible for the Boiler Upgrade Scheme?
Yes. A split air-to-water heat pump counts as an air source heat pump under the scheme, so in England and Wales eligible owners of existing homes can receive £7,500, or £9,000 when replacing oil or LPG within the published dates. The MCS-certified installer applies for you. Scotland's Home Energy Scotland funding is separate, and Northern Ireland has no dedicated homeowner grant at present.
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.