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 Greater London with combi boilers have no airing cupboard, so the survey looks for the most practical cylinder space. Cylinder sizes for Greater London homes are based on the people living there and the bathrooms in daily use. Older houses in Greater London with loft tanks can usually have them removed when an unvented cylinder is fitted.
Who it suits
- Larger families or homes with two or more bathrooms
- Households with older vented cylinders and loft tanks who want mains-pressure showers
- Every air-to-water heat pump installation, whatever the existing boiler
- Homes replacing a combi boiler that need space found for a cylinder
Grants and rules for heat pumps in England
Homes in Greater London 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 Greater London
Here are typical prices for heat pump hot water cylinders in Greater London, 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) | £1,350–£2,450 |
Supplied and fitted, inc VAT. Included in every full system price.
Towns we cover in Greater London
We cover 90 towns in Greater London 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 |
|---|---|---|---|
| Islington | N1 | Highbury | 7 h 49 min |
| Bexley | DA5 | Bexleyheath | 7 h 50 min |
| Barking | IG11 | Ilford | 7 h 49 min |
| Sutton | SM1 | Carshalton | 7 h 51 min |
| Croydon | CR0 | Purley | 7 h 51 min |
| Ilford | IG1 | Barking | 7 h 49 min |
| Harrow | HA1 | Pinner | 7 h 49 min |
| Tottenham | N17 | Wood Green | 7 h 49 min |
| Walthamstow | E17 | Leyton | 7 h 49 min |
| Dagenham | RM10 | Barking | 7 h 49 min |
| Romford | RM1 | Hornchurch | 7 h 49 min |
| Hayes | UB3 | Southall | 7 h 49 min |
| Wembley | HA9 | Hendon | 7 h 49 min |
| Fulham | SW6 | Putney | 7 h 50 min |
| Southall | UB1 | Hayes | 7 h 49 min |
| Putney | SW15 | Fulham | 7 h 50 min |
| Battersea | SW11 | Chelsea | 7 h 50 min |
| Purley | CR8 | Coulsdon | 7 h 51 min |
| Peckham | SE15 | Dulwich | 7 h 50 min |
| Chingford | E4 | Woodford Green | 7 h 48 min |
| Uxbridge | UB8 | Ruislip | 7 h 49 min |
| Wimbledon | SW19 | Morden | 7 h 50 min |
| Brixton | SW2 | Clapham | 7 h 50 min |
| Hounslow | TW3 | Twickenham | 7 h 50 min |
| Finchley | N3 | Hendon | 7 h 49 min |
| Mitcham | CR4 | Morden | 7 h 51 min |
| Feltham | TW13 | Hounslow | 7 h 50 min |
| Acton | W3 | Chiswick | 7 h 49 min |
| Beckenham | BR3 | Bromley | 7 h 50 min |
| Chelsea | SW3 | Battersea | 7 h 50 min |
| Streatham | SW16 | Balham | 7 h 50 min |
| Eltham | SE9 | Blackheath | 7 h 50 min |
| Morden | SM4 | Mitcham | 7 h 51 min |
| Carshalton | SM5 | Sutton | 7 h 51 min |
| Catford | SE6 | Lewisham | 7 h 50 min |
| Surbiton | KT6 | Kingston upon Thames | 7 h 51 min |
| Stratford | E15 | Leyton | 7 h 49 min |
| Chiswick | W4 | Acton | 7 h 50 min |
| Ruislip | HA4 | Pinner | 7 h 49 min |
| Greenwich | SE10 | Blackheath | 7 h 50 min |
| Barnet | EN5 | Mill Hill | 7 h 48 min |
| Wood Green | N22 | Crouch End | 7 h 49 min |
| Muswell Hill | N10 | Crouch End | 7 h 49 min |
| Highbury | N5 | Islington | 7 h 49 min |
| Coulsdon | CR5 | Purley | 7 h 51 min |
| Hornchurch | RM11 | Upminster | 7 h 49 min |
| Blackheath | SE3 | Lewisham | 7 h 50 min |
| New Malden | KT3 | Kingston upon Thames | 7 h 51 min |
| Woodford Green | IG8 | Chingford | 7 h 48 min |
| Richmond | TW9 | Twickenham | 7 h 50 min |
| Barnes | SW13 | Putney | 7 h 50 min |
| Notting Hill | W11 | Kensington | 7 h 49 min |
| Pinner | HA5 | Harrow | 7 h 49 min |
| Golders Green | NW11 | Hampstead | 7 h 49 min |
| Tooting | SW17 | Balham | 7 h 50 min |
| Chislehurst | BR7 | Sidcup | 7 h 50 min |
| Orpington | BR6 | Chislehurst | 7 h 51 min |
| Balham | SW12 | Tooting | 7 h 50 min |
| Bexleyheath | DA6 | Bexley | 7 h 50 min |
| Bromley | BR1 | Beckenham | 7 h 51 min |
| Camden | NW1 | Kentish Town | 7 h 49 min |
| Clapham | SW4 | Brixton | 7 h 50 min |
| Crouch End | N8 | Highgate | 7 h 49 min |
| Dulwich | SE21 | Brixton | 7 h 50 min |
| Ealing | W5 | Acton | 7 h 49 min |
| Edgware | HA8 | Mill Hill | 7 h 48 min |
| Enfield | EN1 | Southgate | 7 h 48 min |
| Forest Hill | SE23 | Sydenham | 7 h 50 min |
| Hackney | E8 | Stoke Newington | 7 h 49 min |
| Hammersmith | W6 | Notting Hill | 7 h 50 min |
| Hampstead | NW3 | West Hampstead | 7 h 49 min |
| Hendon | NW4 | Golders Green | 7 h 49 min |
| Highgate | N6 | Crouch End | 7 h 49 min |
| Kensington | W8 | Notting Hill | 7 h 50 min |
| Kentish Town | NW5 | Camden | 7 h 49 min |
| Kingston upon Thames | KT1 | Surbiton | 7 h 50 min |
| Lewisham | SE13 | Blackheath | 7 h 50 min |
| Leyton | E10 | Walthamstow | 7 h 49 min |
| Mill Hill | NW7 | Edgware | 7 h 48 min |
| Sidcup | DA14 | Chislehurst | 7 h 50 min |
| Southgate | N14 | Enfield | 7 h 48 min |
| Stoke Newington | N16 | Highbury | 7 h 49 min |
| Sydenham | SE26 | Forest Hill | 7 h 50 min |
| Teddington | TW11 | Twickenham | 7 h 50 min |
| Twickenham | TW1 | Teddington | 7 h 50 min |
| Upminster | RM14 | Hornchurch | 7 h 49 min |
| Wandsworth | SW18 | Putney | 7 h 50 min |
| Wanstead | E11 | Leyton | 7 h 49 min |
| West Hampstead | NW6 | Hampstead | 7 h 49 min |
| Woolwich | SE18 | Eltham | 7 h 50 min |
Heat pump hot water cylinders questions
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.
Do I need good water pressure for an unvented cylinder?
Yes. An unvented cylinder runs at mains pressure, so it needs enough incoming pressure and flow to supply your taps and showers well. We measure your mains supply at the survey. If flow is low, options include a different cylinder type or an upgrade to the incoming supply pipe, which we explain before you commit.
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.