The trade-off is efficiency. The hotter the water a heat pump makes, the more electricity it needs for each unit of heat, so a system running at 65°C has a lower seasonal efficiency than one running at 45°C. Good design still matters: weather compensation runs the unit cooler on mild days and only raises the temperature in the coldest weather, which keeps running costs down across the year.
Period houses in Renfrewshire and Inverclyde with original cast-iron radiators may suit a high-temperature unit that works with them. Installers in Renfrewshire and Inverclyde set the weather compensation curve so the unit runs cooler on mild days. A survey in Renfrewshire and Inverclyde can compare a high-temperature unit with upsizing a few radiators, for homes anywhere in Renfrewshire and Inverclyde.
Who it suits
- Rooms with no wall space for a larger radiator
- Older homes where insulation improvements are limited
- Period and listed homes where the radiators are part of the character
- Homes with microbore pipework that would be disruptive to replace
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.
High-temperature heat pumps prices in Renfrewshire and Inverclyde
These are guide prices for Renfrewshire and Inverclyde, 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 | £9,500–£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. A high-temperature unit typically adds £1,500–£3,000. 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 high-temperature 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 |
High-temperature heat pumps questions
Are high-temperature heat pumps less efficient?
Yes, when they run hot. Every heat pump uses more electricity per unit of heat as the flow temperature rises, so a unit running at 70°C is less efficient than one running at 45°C. With weather compensation it runs cooler for much of the year, which narrows the gap. The design aims to keep the maximum temperature as low as your radiators allow.
Can a heat pump work with my existing radiators?
Often, yes, especially with a high-temperature unit. Standard heat pumps run most efficiently at 35–50°C, so some radiators may be too small at those temperatures. A high-temperature unit can run at around 65–75°C, so existing radiators can usually heat rooms much as they do with a boiler, at a cost in efficiency. The survey checks every radiator against its room's heat loss.
Are high-temperature heat pumps eligible for the grant?
In England and Wales, yes. A high-temperature unit is an air-to-water heat pump, so eligible owners of existing homes can receive £7,500 through the Boiler Upgrade Scheme, or £9,000 when replacing oil or LPG within the published dates. Scotland's Home Energy Scotland funding has its own conditions, and Northern Ireland has no dedicated homeowner grant at present.
Do I still need a hot water cylinder?
Yes. Like other air-to-water heat pumps, a high-temperature unit heats a stored cylinder rather than supplying hot water on demand. Its higher output temperature can help the cylinder reach the temperature needed for its periodic legionella cycle with less reliance on the immersion heater. The cylinder is sized for your household at survey.