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 West Sussex with a rear wall close to the cylinder location usually suit a monobloc unit with a short pipe run. In exposed spots around West Sussex, frost protection for the outdoor pipework is chosen with the site in mind. Bungalows in West Sussex often let the unit sit right beside the plant cupboard, keeping water pipes short.
Who it suits
- Households that want to keep refrigerant work out of routine servicing
- Houses and bungalows with outdoor space close to where pipes enter the home
- Homes where the unit can sit within a short pipe run of the cylinder
- Owners who want the simplest installation, with no indoor refrigerant
Grants and rules for heat pumps in England
In England the Boiler Upgrade Scheme gives £7,500 towards an air source heat pump (£9,000 if it replaces oil or LPG, from 21 July 2026 to 31 March 2027), and since 28 April 2026 a valid EPC is no longer needed. The grant is applied for by the MCS-certified installer and shown as a deduction on your quote.
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 West Sussex
Here are typical prices for monobloc heat pumps in West Sussex, 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 | £9,900–£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 West Sussex
We cover 14 towns in West Sussex for monobloc heat pumps. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Crawley | RH11 | Horley | 7 h 53 min |
| Worthing | BN11 | Shoreham-by-Sea | 7 h 56 min |
| Bognor Regis | PO21 | Chichester | 7 h 57 min |
| Littlehampton | BN17 | Arundel | 7 h 56 min |
| Horsham | RH12 | Crawley | 7 h 54 min |
| Haywards Heath | RH16 | Burgess Hill | 7 h 55 min |
| Chichester | PO19 | Bognor Regis | 7 h 56 min |
| Burgess Hill | RH15 | Haywards Heath | 7 h 55 min |
| East Grinstead | RH19 | Crawley | 7 h 53 min |
| Shoreham-by-Sea | BN43 | Worthing | 7 h 56 min |
| Emsworth | PO10 | Havant | 7 h 56 min |
| Arundel | BN18 | Littlehampton | 7 h 56 min |
| Midhurst | GU29 | Petworth | 7 h 55 min |
| Petworth | GU28 | Midhurst | 7 h 55 min |
Monobloc heat pumps questions
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.
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.
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.
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.