- Area
- Hampshire
- Postcode district
- SO14
- Nation
- England
- Guide price
- From £9,800 inc VAT
- Survey
- Free for installation enquiries
What to know about replacing a gas boiler with a heat pump in Southampton
The question for a Southampton 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.
Rear gardens and side returns in Southampton usually offer a sensible spot for the outdoor unit, checked for airflow and neighbours. Households across Hampshire moving off gas can have a survey in Southampton 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.
- Homes in England and Wales eligible for the Boiler Upgrade Scheme
- Households ready to give up gas entirely and drop the standing charge
- Boilers that are old, unreliable or due for replacement
What's included
- System flush and radiator upgrades where the design calls for them
- Heat pump cylinder, outdoor unit and weather compensation controls
- Free survey with heat loss calculation and cylinder siting
- Removal of the gas boiler, flue and any loft tanks
- Capping of the gas pipe at the boiler position where you are giving up gas
Installers in Southampton take out the old boiler and flue and seal the wall opening as part of the job.
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 Southampton quote.
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.
Gas boiler to heat pump costs around Southampton
Guide prices for Southampton and the rest of Hampshire are shown below, installed and inc VAT. We publish ranges rather than a single figure because design details move the price, and the written quote after survey fixes it.
| Home | Typical size | Installed guide price | After £7,500 grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £9,800–£12,900 | £2,300–£5,400 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,800–£13,900 | £3,300–£6,400 |
| 3 bedroom semi or small detached | 6–9 kW | £12,350–£15,950 | £4,850–£8,450 |
| 4 bedroom detached | 8–12 kW | £14,400–£18,550 | £6,900–£11,050 |
| 5+ bedroom or larger older house | 11–16 kW | £17,000–£23,200 | £9,500–£15,700 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Winter daylight and heating in Southampton
On the shortest day Southampton gets about 7 hours 56 minutes of daylight, and the winter sun reaches only around 16° above the horizon at noon. Winters this far south are milder than in most of the UK, which helps a heat pump run at low flow temperatures for much of the season.
What happens after you enquire in Southampton?
- Start online with a guide price or call us.
- A home survey in Southampton 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 Southampton: questions
What size heat pump does a Southampton 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 Southampton home.
Can you service a heat pump in Southampton that someone else installed?
Yes. We arrange servicing and repairs for most air source heat pumps in Southampton, whoever fitted them. Tell us the make and model when you book.
Where would the outdoor unit go on a Southampton 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 Southampton home.
Can a heat pump replace a combi boiler?
Yes, but you need room for a hot water cylinder, because heat pumps store hot water rather than heating it on demand. Most homes find a space in a cupboard, utility room, garage or under the stairs, and compact or combined indoor units help where space is tight. The survey measures the options first, so you know where everything will go before you accept the quote.
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.