- Area
- West Sussex
- Postcode district
- RH12
- Nation
- England
- Guide price
- From £9,900 inc VAT
- Survey
- Free for installation enquiries
Gas boiler to heat pump for Horsham homes
A heat pump suits most Horsham homes, but the details decide how efficiently it runs. Our survey looks at insulation, radiators and hot water use room by room.
Installers in Horsham take out the old boiler and flue and seal the wall opening as part of the job. Many gas-heated homes in Horsham have a combi boiler in the kitchen, so the survey starts by finding the right place for a cylinder.
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.
- Homes in England and Wales eligible for the Boiler Upgrade Scheme
- Boilers that are old, unreliable or due for replacement
- Combi owners who can find space for a hot water cylinder
What's included
- Capping of the gas pipe at the boiler position where you are giving up gas
- Commissioning, MCS certificate and grant application in England and Wales where eligible
- Removal of the gas boiler, flue and any loft tanks
- Free survey with heat loss calculation and cylinder siting
- Heat pump cylinder, outdoor unit and weather compensation controls
Households across West Sussex moving off gas can have a survey in Horsham that compares running costs on realistic assumptions.
Grants and rules for heat pumps in England
In England the Boiler Upgrade Scheme gives £7,500 towards an air source heat pump (£9,000 if it replaces oil or LPG, from 21 July 2026 to 31 March 2027), and since 28 April 2026 a valid EPC is no longer needed. The grant is applied for by the MCS-certified installer and shown as a deduction on your Horsham quote.
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.
What to budget for replacing a gas boiler with a heat pump in Horsham
The ranges below are typical installed prices for homes in West Sussex, including VAT. A survey sets the exact figure, because two similar-looking houses in Horsham can need quite different radiators and pipework.
| Home | Typical size | Installed guide price | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,900–£13,000 | £2,400–£5,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,900–£14,050 | £3,400–£6,550 |
| 3 bedroom semi or small detached | 6–9 kW | £12,500–£16,100 | £5,000–£8,600 |
| 4 bedroom detached | 8–12 kW | £14,550–£18,700 | £7,050–£11,200 |
| 5+ bedroom or larger older house | 11–16 kW | £17,150–£23,400 | £9,650–£15,900 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Short winter days in Horsham and what they mean
Horsham sees roughly 7 hours 54 minutes of daylight in late December against 16 hours 33 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.
What happens after you enquire in Horsham?
- Start online with a guide price or call us.
- A home survey in Horsham gives us the room-by-room heat loss.
- Your written quote sets out the design, the price and the grant position where you live.
- Installation is booked for dates that suit you; most homes take 2–4 days on site.
- After commissioning you get a handover of the controls and settings, plus the certificates.
Replacing a gas boiler with a heat pump in Horsham: questions
How long does installation take in Horsham?
Most installations take 2–4 days on site. Jobs with several radiator changes or new pipework take longer, and your quote for a Horsham home states the expected time.
How soon can you survey a home in Horsham?
Survey dates depend on how busy installers are in West Sussex. We offer the next available dates when you enquire and confirm them in writing.
How long does a heat pump survey take in Horsham?
A home survey in Horsham usually takes one to two hours. The surveyor measures every heated room, checks windows, walls and radiators, and looks at where the outdoor unit and cylinder can go.
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.
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.