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.
Semi-detached homes in Perth and Kinross often have a side wall where a monobloc unit can sit on a frame, clear of the path. In exposed spots around Perth and Kinross, frost protection for the outdoor pipework is chosen with the site in mind. Bungalows in Perth and Kinross often let the unit sit right beside the plant cupboard, keeping water pipes short.
Who it suits
- Homes where the unit can sit within a short pipe run of the cylinder
- 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
Grants and rules for heat pumps in Scotland
In Scotland, heat pump funding comes through Home Energy Scotland rather than the Boiler Upgrade Scheme: a grant of up to £7,500 (up to £1,500 extra for eligible rural and island homes) and an optional interest-free loan of up to £7,500. For a home in Perth and Kinross, apply and receive the written offer before the installation date is fixed.
Installing heat pumps is zero-rated for VAT across the UK until 31 March 2027. Scotland has its own permitted development rules for air source heat pumps and its own building standards, so we confirm what applies to your property at survey.
Monobloc heat pumps prices in Perth and Kinross
These are guide prices for Perth and Kinross, installed and including VAT. Your final price is fixed in a written quote after the survey and depends on the heat loss of the house, the radiators that need changing and where the unit goes.
| Home | Typical size | Installed guide price |
|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,600–£12,650 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,600–£13,650 |
| 3 bedroom semi or small detached | 6–9 kW | £12,100–£15,650 |
| 4 bedroom detached | 8–12 kW | £14,150–£18,200 |
| 5+ bedroom or larger older house | 11–16 kW | £16,650–£22,750 |
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 Perth and Kinross
We cover 7 towns in Perth and Kinross for monobloc heat pumps. Each links to local guide prices and the grant position for Scotland.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Perth | PH2 | Auchterarder | 6 h 51 min |
| Aberfeldy | PH15 | Pitlochry | 6 h 48 min |
| Auchterarder | PH3 | Crieff | 6 h 53 min |
| Blairgowrie | PH10 | Perth | 6 h 48 min |
| Crieff | PH7 | Auchterarder | 6 h 52 min |
| Kinross | KY13 | Dunfermline | 6 h 54 min |
| Pitlochry | PH16 | Aberfeldy | 6 h 47 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 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.
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.