- Area
- Greater London
- Postcode district
- UB1
- Nation
- England
- Guide price
- From £10,650 inc VAT
- Survey
- Free for installation enquiries
Gas boiler to heat pump for Southall homes
The question for a Southall home is rarely whether a heat pump can work, but what needs to change to make it work well: radiator sizes, pipework, controls and where the unit goes.
Installers in Southall take out the old boiler and flue and seal the wall opening as part of the job. Households across Greater London moving off gas can have a survey in Southall that compares running costs on realistic assumptions.
Moving from mains gas to a heat pump means finding cylinder space, deciding what happens to the gas supply and comparing running costs on realistic assumptions.
- System or regular boiler homes with an existing airing cupboard
- Households ready to give up gas entirely and drop the standing charge
- Boilers that are old, unreliable or due for replacement
What's included
- Commissioning, MCS certificate and grant application in England and Wales where eligible
- Free survey with heat loss calculation and cylinder siting
- System flush and radiator upgrades where the design calls for them
- Heat pump cylinder, outdoor unit and weather compensation controls
- Removal of the gas boiler, flue and any loft tanks
Semi-detached and terraced houses in Southall often have an airing cupboard that can be reused for a heat pump cylinder.
Grants and rules for heat pumps in England
Homes in Southall 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.
Guide prices for replacing a gas boiler with a heat pump in Southall
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.
Winter daylight and heating in Southall
Southall sees roughly 7 hours 49 minutes of daylight in late December against 16 hours 38 minutes in June. Milder southern winters suit heat pumps well, though the system is still sized for a cold snap rather than an average day.
How installation works in Southall
- Tell us about your home: postcode, property type and current heating.
- We book a survey in Southall; the surveyor measures rooms, windows and radiators and looks at cylinder space.
- The design and quote arrive in writing, including radiator changes and the outdoor unit position.
- On installation days the old system is removed and the new one fitted and filled.
- We commission the heat pump, show you the controls and register the installation.
Replacing a gas boiler with a heat pump in Southall: questions
Where would the outdoor unit go on a Southall house?
Usually at the side or rear, on a level base with space around it for airflow and servicing, away from bedroom windows where possible. The surveyor checks positions at your Southall home.
How long does installation take in Southall?
Most installations take 2–4 days on site. Jobs with several radiator changes or new pipework take longer, and your quote for a Southall home states the expected time.
What size heat pump does a Southall home need?
It depends on the heat loss, not the postcode. As a rough guide, a 3 bedroom semi often needs 6–9 kW, but the room-by-room survey sets the actual size for your Southall home.
Do I need to replace the cylinder I already have?
Usually, yes. Older cylinders have a small internal coil designed for water from a boiler at around 60–70°C, and they cannot take in heat quickly enough at the lower temperatures a heat pump runs at. A heat pump cylinder has a larger coil. On its own, a cylinder supplied and fitted has a guide price of £1,200–£2,200, installed and including VAT, though it is normally part of the full system price.
Is there a grant to replace a gas boiler with a heat pump?
In England and Wales, the Boiler Upgrade Scheme gives £7,500 towards an air-to-water heat pump that replaces a gas boiler, for eligible owners of existing homes. The MCS-certified installer applies to Ofgem and deducts the grant from your quote, and Ofgem contacts you to confirm. Scotland has separate Home Energy Scotland funding, and Northern Ireland has no dedicated homeowner grant at present.