A monobloc heat pump is an air-to-water unit with the entire refrigerant circuit, including the compressor, heat exchangers and refrigerant, sealed inside the outdoor casing. Heat is passed to water inside the unit, and insulated water pipes carry it into the house to the cylinder and heating system. Nothing containing refrigerant comes indoors, which is a big part of why monobloc units suit so many UK homes.
For Greater London terraces with small yards, the survey confirms the unit fits with the clearances it needs. A survey in Greater London checks the unit position, pipe route and clearance zones together for homes across Greater London. Bungalows in Greater London often let the unit sit right beside the plant cupboard, keeping water pipes short.
Who it suits
- Owners who want the simplest installation, with no indoor refrigerant
- Households that want to keep refrigerant work out of routine servicing
- Houses and bungalows with outdoor space close to where pipes enter the home
- Homes where the unit can sit within a short pipe run of the 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.
Monobloc heat pumps prices in Greater London
These are guide prices for Greater London, 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 | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £10,650–£14,000 | £3,150–£6,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £11,750–£15,100 | £4,250–£7,600 |
| 3 bedroom semi or small detached | 6–9 kW | £13,450–£17,350 | £5,950–£9,850 |
| 4 bedroom detached | 8–12 kW | £15,700–£20,150 | £8,200–£12,650 |
| 5+ bedroom or larger older house | 11–16 kW | £18,500–£25,200 | £11,000–£17,700 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Towns we cover in Greater London
We cover 90 towns in Greater London for monobloc heat pumps. 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 |
Monobloc heat pumps questions
How far can a monobloc unit be from the house?
Usually as close as practical, because water pipes outside lose heat and need frost protection. Manufacturers set limits on pipe length and size, and longer runs need larger, better-insulated pipes. Most homes site the unit against or near an outside wall close to where the pipes enter. If the only good position is far from the house, a split system may suit better.
Do monobloc heat pumps need an F-gas engineer?
For a typical installation no refrigerant work is needed on site, because the refrigerant circuit is sealed in the outdoor unit at the factory. That is one reason monobloc installs are simpler. If the sealed circuit ever develops a fault or leak, any repair to it must be done by an F-gas certified engineer, as with every refrigerant system.
Is glycol or anti-freeze valves the better option?
Neither is right for every home. Glycol gives reliable frost protection without draining but slightly reduces efficiency and needs its concentration checked at servicing. Anti-freeze valves keep the system water plain but release water if pipes near freezing during a power cut, so the system then needs refilling. The installer recommends one based on the unit, pipe run and how exposed the site is.
What refrigerant do monobloc heat pumps use?
Most use R32 or R290. R290 is propane, a natural refrigerant with a very low global warming impact, and some models use it to reach higher flow temperatures. Because R290 is flammable, manufacturers set clearance zones around the unit from openings such as windows, doors and drains, which the survey takes into account when choosing a position.