- Area
- Hertfordshire
- Postcode district
- AL8
- Nation
- England
- Guide price
- From £10,000 inc VAT
- Survey
- Free for installation enquiries
Gas boiler to heat pump for Welwyn Garden City homes
A heat pump suits most Welwyn Garden City homes, but the details decide how efficiently it runs. Our survey looks at insulation, radiators and hot water use room by room.
Households across Hertfordshire moving off gas can have a survey in Welwyn Garden City that compares running costs on realistic assumptions. Installers in Welwyn Garden City 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
- System or regular boiler homes with an existing airing cupboard
- Households ready to give up gas entirely and drop the standing charge
What's included
- Free survey with heat loss calculation and cylinder siting
- Commissioning, MCS certificate and grant application in England and Wales where eligible
- Removal of the gas boiler, flue and any loft tanks
- Heat pump cylinder, outdoor unit and weather compensation controls
- System flush and radiator upgrades where the design calls for them
Rear gardens and side returns in Welwyn Garden City usually offer a sensible spot for the outdoor unit, checked for airflow and neighbours.
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 Welwyn Garden City 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.
What to budget for replacing a gas boiler with a heat pump in Welwyn Garden City
The ranges below are typical installed prices for homes in Hertfordshire, including VAT. A survey sets the exact figure, because two similar-looking houses in Welwyn Garden City 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 | £10,000–£13,150 | £2,500–£5,650 |
| 2–3 bedroom terrace or semi | 5–7 kW | £11,050–£14,200 | £3,550–£6,700 |
| 3 bedroom semi or small detached | 6–9 kW | £12,600–£16,300 | £5,100–£8,800 |
| 4 bedroom detached | 8–12 kW | £14,700–£18,900 | £7,200–£11,400 |
| 5+ bedroom or larger older house | 11–16 kW | £17,350–£23,650 | £9,850–£16,150 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Short winter days in Welwyn Garden City and what they mean
On the shortest day Welwyn Garden City gets about 7 hours 46 minutes of daylight, with the noon sun around 15° up. The heating season runs from autumn into spring, so a heat pump that is sized correctly and set up with weather compensation does most of its work in steady, cool conditions.
What happens after you enquire in Welwyn Garden City?
- Send your postcode and a few details, or use the guide price tool.
- A surveyor visits your Welwyn Garden City home, measures every room and checks where the outdoor unit can go.
- You receive a heat loss design and a fixed written quote, with any grant shown where it applies.
- Installers fit the unit, cylinder and any radiator changes, typically over 2–4 days on site.
- The system is commissioned, set up with weather compensation and handed over with the paperwork.
Replacing a gas boiler with a heat pump in Welwyn Garden City: questions
How long does installation take in Welwyn Garden City?
Most installations take 2–4 days on site. Jobs with several radiator changes or new pipework take longer, and your quote for a Welwyn Garden City home states the expected time.
Can you service a heat pump in Welwyn Garden City that someone else installed?
Yes. We arrange servicing and repairs for most air source heat pumps in Welwyn Garden City, whoever fitted them. Tell us the make and model when you book.
Do you cover Hatfield as well as Welwyn Garden City?
Yes. We arrange surveys and installation in Hatfield, which is about 3 miles south of Welwyn Garden City, and across Hertfordshire.
What if my gas boiler is fairly new?
A newer boiler can still be replaced, but the timing is worth weighing. Some owners switch when the boiler needs a major repair; others prefer to plan the change for a convenient time. Across the UK, heat pump installation is zero-rated for VAT until 31 March 2027. A hybrid system, which keeps the boiler alongside a heat pump, is another option, though it is not eligible for the Boiler Upgrade Scheme in England and Wales.
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.