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.
In exposed spots around Merseyside, frost protection for the outdoor pipework is chosen with the site in mind. Bungalows in Merseyside often let the unit sit right beside the plant cupboard, keeping water pipes short. Houses in Merseyside 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
- Houses and bungalows with outdoor space close to where pipes enter the home
- Owners who want the simplest installation, with no indoor refrigerant
- Homes where the unit can sit within a short pipe run of the cylinder
Grants and rules for heat pumps in England
Homes in Merseyside 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.
Installing heat pumps is zero-rated for VAT across the UK until 31 March 2027. Since 29 May 2025, permitted development in England allows up to two air source heat pumps on a house, each up to 1.5 m³, with no blanket 1 m boundary rule — the installation must still meet the MCS planning standards, including the noise check. Listed buildings, flats and some conservation-area positions need extra consent, which we check at survey.
Monobloc heat pumps prices in Merseyside
The ranges below are typical installed prices for homes in Merseyside, including VAT. A survey sets the exact figure, because two similar-looking houses in Merseyside 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 | £9,200–£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 Merseyside
We cover 14 towns in Merseyside for monobloc heat pumps. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Liverpool | L3 | Birkenhead | 7 h 29 min |
| Birkenhead | CH41 | Liverpool | 7 h 29 min |
| St Helens | WA10 | Prescot | 7 h 29 min |
| Southport | PR8 | Formby | 7 h 26 min |
| Wallasey | CH45 | Birkenhead | 7 h 29 min |
| Bootle | L21 | Wallasey | 7 h 28 min |
| Bebington | CH63 | Birkenhead | 7 h 30 min |
| Huyton | L36 | Prescot | 7 h 29 min |
| Kirkby | L32 | Maghull | 7 h 28 min |
| Prescot | L34 | Huyton | 7 h 29 min |
| Heswall | CH60 | Bebington | 7 h 30 min |
| Maghull | L31 | Kirkby | 7 h 28 min |
| Formby | L37 | Maghull | 7 h 27 min |
| Halewood | L26 | Huyton | 7 h 30 min |
Monobloc heat pumps questions
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.
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.
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.