- Area
- Gloucestershire
- Postcode district
- BS35
- Nation
- England
- Guide price
- From £9,600 inc VAT
- Survey
- Free for installation enquiries
Gas boiler to heat pump in Thornbury: what to expect
A heat pump suits most Thornbury homes, but the details decide how efficiently it runs. Our survey looks at insulation, radiators and hot water use room by room.
Households across Gloucestershire moving off gas can have a survey in Thornbury that compares running costs on realistic assumptions. Installers in Thornbury take out the old boiler and flue and seal the wall opening as part of the job.
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
- Households ready to give up gas entirely and drop the standing charge
What's included
- Free survey with heat loss calculation and cylinder siting
- Capping of the gas pipe at the boiler position where you are giving up gas
- Removal of the gas boiler, flue and any loft tanks
- Heat pump cylinder, outdoor unit and weather compensation controls
- Commissioning, MCS certificate and grant application in England and Wales where eligible
Many gas-heated homes in Thornbury have a combi boiler in the kitchen, so the survey starts by finding the right place for a cylinder.
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 Thornbury 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.
Gas boiler to heat pump costs around Thornbury
Guide prices for Thornbury and the rest of Gloucestershire 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 | £9,600–£12,650 | £2,100–£5,150 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,600–£13,650 | £3,100–£6,150 |
| 3 bedroom semi or small detached | 6–9 kW | £12,100–£15,650 | £4,600–£8,150 |
| 4 bedroom detached | 8–12 kW | £14,150–£18,200 | £6,650–£10,700 |
| 5+ bedroom or larger older house | 11–16 kW | £16,650–£22,750 | £9,150–£15,250 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
How long is the heating season in Thornbury?
Thornbury has about 7 hours 48 minutes of daylight at midwinter and 16 hours 40 minutes at midsummer. That swing matters if you pair a heat pump with solar panels: summer generation can cover much of the hot water, winter generation far less.
From survey to switch-on in Thornbury
- Tell us about your home: postcode, property type and current heating.
- We book a survey in Thornbury; 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 Thornbury: questions
What size heat pump does a Thornbury 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 Thornbury home.
How long does installation take in Thornbury?
Most installations take 2–4 days on site. Jobs with several radiator changes or new pipework take longer, and your quote for a Thornbury home states the expected time.
Can you service a heat pump in Thornbury that someone else installed?
Yes. We arrange servicing and repairs for most air source heat pumps in Thornbury, whoever fitted them. Tell us the make and model when you book.
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.
Will my hot water run out with a heat pump?
Not if the cylinder is sized properly for your household. The survey asks how many people live in the home, how many bathrooms you have and whether you prefer baths or showers, then sizes the cylinder to suit. The heat pump reheats the cylinder on a schedule, often overnight and again during the day, and an immersion heater acts as a backup.