The trade-off is that the pipes between the outdoor unit and the house carry water, so they must be protected from freezing. That is done with glycol (an anti-freeze) in the system or with anti-freeze valves that release water from the outdoor pipework if it nears freezing, for example during a power cut in cold weather. Keeping the outdoor pipe run short and well insulated also helps efficiency.
Semi-detached homes in County Durham often have a side wall where a monobloc unit can sit on a frame, clear of the path. Bungalows in County Durham often let the unit sit right beside the plant cupboard, keeping water pipes short. Houses in County Durham with a rear wall close to the cylinder location usually suit a monobloc unit with a short pipe run.
Who it suits
- Households that want to keep refrigerant work out of routine servicing
- 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
- Owners who want the simplest installation, with no indoor refrigerant
Grants and rules for heat pumps in England
Homes in County Durham 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.
Monobloc heat pumps prices in County Durham
Here are typical prices for monobloc heat pumps in County Durham, 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 | £9,200–£12,150 | £1,700–£4,650 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,200–£13,100 | £2,700–£5,600 |
| 3 bedroom semi or small detached | 6–9 kW | £11,650–£15,050 | £4,150–£7,550 |
| 4 bedroom detached | 8–12 kW | £13,600–£17,450 | £6,100–£9,950 |
| 5+ bedroom or larger older house | 11–16 kW | £16,000–£21,850 | £8,500–£14,350 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Towns we cover in County Durham
We cover 14 towns in County Durham for monobloc heat pumps. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Darlington | DL1 | Newton Aycliffe | 7 h 16 min |
| Hartlepool | TS26 | Peterlee | 7 h 14 min |
| Stockton-on-Tees | TS18 | Billingham | 7 h 15 min |
| Durham | DH1 | Chester-le-Street | 7 h 13 min |
| Chester-le-Street | DH2 | Stanley | 7 h 12 min |
| Billingham | TS23 | Stockton-on-Tees | 7 h 15 min |
| Stanley | DH9 | Chester-le-Street | 7 h 12 min |
| Consett | DH8 | Stanley | 7 h 12 min |
| Newton Aycliffe | DL5 | Bishop Auckland | 7 h 15 min |
| Bishop Auckland | DL14 | Newton Aycliffe | 7 h 14 min |
| Seaham | SR7 | Peterlee | 7 h 12 min |
| Peterlee | SR8 | Seaham | 7 h 13 min |
| Barnard Castle | DL12 | Bishop Auckland | 7 h 16 min |
| Sedgefield | TS21 | Newton Aycliffe | 7 h 14 min |
Monobloc heat pumps questions
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.
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.
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.
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.