Most heat pump cylinders are unvented, meaning they run at mains water pressure and give strong flow from every tap without a cold water tank in the loft. Unvented cylinders have safety controls that must be fitted and checked by someone qualified to work on them. We size the cylinder from your household and bathrooms, confirm your mains water supply can support it, and plan the space, pipework and discharge route at the survey.
Many homes in East Sussex with combi boilers have no airing cupboard, so the survey looks for the most practical cylinder space. Discharge pipe routes are planned at the survey so an East Sussex cylinder can drain safely to the outside. Cylinder sizes for East Sussex homes are based on the people living there and the bathrooms in daily use.
Who it suits
- Homes replacing a combi boiler that need space found for a cylinder
- Larger families or homes with two or more bathrooms
- Every air-to-water heat pump installation, whatever the existing boiler
- Homes with solar PV that want to store daytime electricity as hot water
Grants and rules for heat pumps in England
Homes in East Sussex 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.
Heat pump hot water cylinders prices in East Sussex
Here are typical prices for heat pump hot water cylinders 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.
| Work | Guide price |
|---|---|
| Heat pump hot water cylinder (supplied and fitted) | £1,250–£2,250 |
Supplied and fitted, inc VAT. Included in every full system price.
Towns we cover in East Sussex
We cover 14 towns in East Sussex for heat pump hot water cylinders. 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 |
Heat pump hot water cylinders questions
I have a combi boiler. Where will the cylinder go?
Moving from a combi to a heat pump means finding space for a cylinder, usually somewhere around 600 mm square and up to about 2 m tall. Common choices are a bedroom or landing cupboard, a utility room, under the stairs or an integral garage. The surveyor looks at your layout and suggests options, including slimline models where space is tight.
How much does a heat pump cylinder cost?
A heat pump hot water cylinder has a guide price of £1,200–£2,200, installed and including VAT. In a full heat pump installation the cylinder is already included in the system guide price, so this figure mainly applies where a cylinder is replaced on its own. Capacity, coil design and the pipework needed affect where your price sits.
Can I keep my existing hot water cylinder with a heat pump?
Usually not. Cylinders designed for boilers have a small coil that cannot transfer heat quickly at heat pump temperatures, so the water would reheat slowly and efficiency would suffer. A heat pump cylinder has a much larger coil. The new cylinder can often go in the same cupboard, though, if there is enough height and floor space.
Will I run out of hot water with a heat pump?
Not if the cylinder is sized to how your household uses hot water. Unlike a combi, hot water is stored, so very heavy use, such as several long showers back to back, can use up the stored volume before it reheats. Sizing for your busiest period, and timing reheats sensibly, avoids this for most homes.

