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 West Sussex with combi boilers have no airing cupboard, so the survey looks for the most practical cylinder space. Older houses in West Sussex with loft tanks can usually have them removed when an unvented cylinder is fitted. In terraced homes around West Sussex and across West Sussex, slimline cylinders can fit spaces a standard model cannot.
Who it suits
- Homes with solar PV that want to store daytime electricity as hot water
- Larger families or homes with two or more bathrooms
- Homes replacing a combi boiler that need space found for a cylinder
- Households with older vented cylinders and loft tanks who want mains-pressure showers
Grants and rules for heat pumps in England
Homes in West 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.
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.
Heat pump hot water cylinders prices in West Sussex
These are guide prices for West Sussex, 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.
| Work | Guide price |
|---|---|
| Heat pump hot water cylinder (supplied and fitted) | £1,250–£2,300 |
Supplied and fitted, inc VAT. Included in every full system price.
Towns we cover in West Sussex
We cover 14 towns in West 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 |
|---|---|---|---|
| Crawley | RH11 | Horley | 7 h 53 min |
| Worthing | BN11 | Shoreham-by-Sea | 7 h 56 min |
| Bognor Regis | PO21 | Chichester | 7 h 57 min |
| Littlehampton | BN17 | Arundel | 7 h 56 min |
| Horsham | RH12 | Crawley | 7 h 54 min |
| Haywards Heath | RH16 | Burgess Hill | 7 h 55 min |
| Chichester | PO19 | Bognor Regis | 7 h 56 min |
| Burgess Hill | RH15 | Haywards Heath | 7 h 55 min |
| East Grinstead | RH19 | Crawley | 7 h 53 min |
| Shoreham-by-Sea | BN43 | Worthing | 7 h 56 min |
| Emsworth | PO10 | Havant | 7 h 56 min |
| Arundel | BN18 | Littlehampton | 7 h 56 min |
| Midhurst | GU29 | Petworth | 7 h 55 min |
| Petworth | GU28 | Midhurst | 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.
Does a heat pump cylinder need servicing?
Yes. An unvented cylinder's safety devices should be checked every year, including the relief valves, the expansion vessel charge and the discharge pipework. This is normally done as part of the annual heat pump service, and it is often a condition of the cylinder manufacturer's warranty. Keep the cylinder paperwork with your heat pump handover documents.