- Area
- Dyfed
- Postcode district
- SA31
- Nation
- Wales
- Guide price
- From £9,500 inc VAT
- Survey
- Free for installation enquiries
What to know about replacing a gas boiler with a heat pump in Carmarthen
A heat pump suits most Carmarthen homes, but the details decide how efficiently it runs. Our survey looks at insulation, radiators and hot water use room by room.
Rear gardens and side returns in Carmarthen usually offer a sensible spot for the outdoor unit, checked for airflow and neighbours. Many gas-heated homes in Carmarthen 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
- System or regular boiler homes with an existing airing cupboard
- Combi owners who can find space for a hot water cylinder
What's included
- Heat pump cylinder, outdoor unit and weather compensation controls
- Removal of the gas boiler, flue and any loft tanks
- 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
Households across Dyfed moving off gas can have a survey in Carmarthen that compares running costs on realistic assumptions.
Grants and rules for heat pumps in Wales
Homes in Carmarthen can use the Boiler Upgrade Scheme, which applies in Wales as well as England: £7,500 towards an air source heat pump, or £9,000 when it replaces oil or LPG heating for installations from 21 July 2026 to 31 March 2027. The MCS-certified installer named in your quote applies and deducts the grant.
There is no VAT on installing a heat pump anywhere in the UK, Wales included, until 31 March 2027. Planning rules for heat pumps in Wales are set by the Welsh Government and differ from England's, so the surveyor checks the unit position against them.
What to budget for replacing a gas boiler with a heat pump in Carmarthen
Guide prices for Carmarthen and the rest of Dyfed 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 | £9,500–£12,500 | £2,000–£5,000 |
| 2–3 bedroom terrace or semi | 5–7 kW | £10,500–£13,500 | £3,000–£6,000 |
| 3 bedroom semi or small detached | 6–9 kW | £12,000–£15,500 | £4,500–£8,000 |
| 4 bedroom detached | 8–12 kW | £14,000–£18,000 | £6,500–£10,500 |
| 5+ bedroom or larger older house | 11–16 kW | £16,500–£22,500 | £9,000–£15,000 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning.
Short winter days in Carmarthen and what they mean
On the shortest day Carmarthen 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 Carmarthen?
- Start online with a guide price or call us.
- A home survey in Carmarthen 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 Carmarthen: questions
Do you cover Llanelli as well as Carmarthen?
Yes. We arrange surveys and installation in Llanelli, which is about 13 miles south-east of Carmarthen, and across Dyfed.
Can you service a heat pump in Carmarthen that someone else installed?
Yes. We arrange servicing and repairs for most air source heat pumps in Carmarthen, whoever fitted them. Tell us the make and model when you book.
How long does a heat pump survey take in Carmarthen?
A home survey in Carmarthen 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.
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.
Should I have my gas meter removed?
If gas is used for nothing else, removing the meter ends the gas standing charge, which is about £108 a year at the October to December 2026 price cap. If you still cook on gas or have a gas fire, you will need to keep the supply. Meter removal is arranged through your gas supplier, usually once the heat pump is running; the pipe at the boiler position is capped during the installation.