A monobloc heat pump is an air-to-water unit with the entire refrigerant circuit, including the compressor, heat exchangers and refrigerant, sealed inside the outdoor casing. Heat is passed to water inside the unit, and insulated water pipes carry it into the house to the cylinder and heating system. Nothing containing refrigerant comes indoors, which is a big part of why monobloc units suit so many UK homes.
Houses in Renfrewshire and Inverclyde with a rear wall close to the cylinder location usually suit a monobloc unit with a short pipe run. For Renfrewshire and Inverclyde terraces with small yards, the survey confirms the unit fits with the clearances it needs. Bungalows in Renfrewshire and Inverclyde often let the unit sit right beside the plant cupboard, keeping water pipes short.
Who it suits
- Owners who want the simplest installation, with no indoor refrigerant
- 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
Grants and rules for heat pumps in Scotland
The Boiler Upgrade Scheme does not apply in Scotland. Instead, homeowners in Renfrewshire and Inverclyde can apply to Home Energy Scotland for a grant of up to £7,500 towards a heat pump, with up to £1,500 more for eligible rural and island homes, plus an optional interest-free loan of up to £7,500. You need a written funding offer before any work starts.
There is no VAT on installing a heat pump anywhere in the UK, Scotland included, until 31 March 2027. Scottish permitted development rules and building standards apply, and the surveyor checks the unit position and any listed or conservation-area constraints.
Monobloc heat pumps prices in Renfrewshire and Inverclyde
Here are typical prices for monobloc heat pumps in Renfrewshire and Inverclyde, 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 |
|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,500–£12,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,500–£13,500 |
| 3 bedroom semi or small detached | 6–9 kW | £12,000–£15,500 |
| 4 bedroom detached | 8–12 kW | £14,000–£18,000 |
| 5+ bedroom or larger older house | 11–16 kW | £16,500–£22,500 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning. In Scotland, Home Energy Scotland grants of up to £7,500 and interest-free loans may reduce the cost.
Towns we cover in Renfrewshire and Inverclyde
We cover 10 towns in Renfrewshire and Inverclyde for monobloc heat pumps. Each links to local guide prices and the grant position for Scotland.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Paisley | PA2 | Barrhead | 6 h 59 min |
| Greenock | PA15 | Gourock | 6 h 57 min |
| Newton Mearns | G77 | Barrhead | 7 h 00 min |
| Renfrew | PA4 | Erskine | 6 h 58 min |
| Barrhead | G78 | Paisley | 6 h 59 min |
| Johnstone | PA5 | Bridge of Weir | 6 h 59 min |
| Erskine | PA8 | Renfrew | 6 h 58 min |
| Bridge of Weir | PA11 | Johnstone | 6 h 59 min |
| Gourock | PA19 | Greenock | 6 h 57 min |
| Port Glasgow | PA14 | Greenock | 6 h 58 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 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.
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.
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.