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.
For older East Sussex homes with microbore pipework, a higher flow temperature can avoid lifting floors to replace pipes. In East Sussex, rooms with large bay windows are often the ones where radiator output is checked most carefully. Period houses in East Sussex with original cast-iron radiators may suit a high-temperature unit that works with them.
Who it suits
- Rooms with no wall space for a larger radiator
- Owners who want fewer changes inside the house
- 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 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.
High-temperature heat pumps prices in East Sussex
Here are typical prices for high-temperature heat pumps in East 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 | £9,800–£12,900 | £2,300–£5,400 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,800–£13,900 | £3,300–£6,400 |
| 3 bedroom semi or small detached | 6–9 kW | £12,350–£15,950 | £4,850–£8,450 |
| 4 bedroom detached | 8–12 kW | £14,400–£18,550 | £6,900–£11,050 |
| 5+ bedroom or larger older house | 11–16 kW | £17,000–£23,200 | £9,500–£15,700 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning. A high-temperature unit typically adds £1,500–£3,000.
Towns we cover in East Sussex
We cover 14 towns in East Sussex for high-temperature heat pumps. Each links to local guide prices and the grant position for England.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Brighton | BN1 | Peacehaven | 7 h 56 min |
| Eastbourne | BN21 | Hailsham | 7 h 57 min |
| Hastings | TN34 | Bexhill-on-Sea | 7 h 56 min |
| Bexhill-on-Sea | TN40 | Battle | 7 h 56 min |
| Hailsham | BN27 | Eastbourne | 7 h 56 min |
| Seaford | BN25 | Newhaven | 7 h 57 min |
| Crowborough | TN6 | Uckfield | 7 h 54 min |
| Peacehaven | BN10 | Newhaven | 7 h 57 min |
| Uckfield | TN22 | Crowborough | 7 h 55 min |
| Lewes | BN7 | Peacehaven | 7 h 56 min |
| Battle | TN33 | Bexhill-on-Sea | 7 h 55 min |
| Heathfield | TN21 | Uckfield | 7 h 55 min |
| Newhaven | BN9 | Seaford | 7 h 57 min |
| Rye | TN31 | Hastings | 7 h 55 min |
High-temperature heat pumps questions
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.
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.
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.