Every air-to-water heat pump installation needs a cylinder, because there is no heat pump equivalent of a combi boiler that heats water instantly. If you have a combi now, the main design question is where the cylinder will go. If you already have a cylinder, it will almost always need replacing with a heat pump model, though the same cupboard can often be reused if it is large enough.
We check mains water pressure and flow at each South Glamorgan property before choosing a cylinder. Many homes in South Glamorgan with combi boilers have no airing cupboard, so the survey looks for the most practical cylinder space. In terraced homes around South Glamorgan and across South Glamorgan, slimline cylinders can fit spaces a standard model cannot.
Who it suits
- Larger families or homes with two or more bathrooms
- Households with older vented cylinders and loft tanks who want mains-pressure showers
- Homes with solar PV that want to store daytime electricity as hot water
- Homes replacing a combi boiler that need space found for a cylinder
Grants and rules for heat pumps in Wales
Homes in South Glamorgan 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.
Installing heat pumps is zero-rated for VAT across the UK until 31 March 2027. Wales has its own permitted development rules for air source heat pumps, so we check what applies to your property, including listed building and conservation-area constraints, at the survey.
Heat pump hot water cylinders prices in South Glamorgan
Here are typical prices for heat pump hot water cylinders in South Glamorgan, installed and including VAT. Use the guide price tool for a figure based on your home, then a survey confirms it in writing.
| Work | Guide price |
|---|---|
| Heat pump hot water cylinder (supplied and fitted) | £1,200–£2,200 |
Supplied and fitted, inc VAT. Included in every full system price.
Towns we cover in South Glamorgan
We cover 6 towns in South Glamorgan for heat pump hot water cylinders. Each links to local guide prices and the grant position for Wales.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Cardiff | CF10 | Penarth | 7 h 50 min |
| Barry | CF62 | Dinas Powys | 7 h 51 min |
| Penarth | CF64 | Dinas Powys | 7 h 50 min |
| Cowbridge | CF71 | Llantwit Major | 7 h 50 min |
| Dinas Powys | CF64 | Penarth | 7 h 50 min |
| Llantwit Major | CF61 | Cowbridge | 7 h 50 min |
Heat pump hot water cylinders questions
I have a combi boiler. Where will the cylinder go?
Moving from a combi to a heat pump means finding space for a cylinder, usually somewhere around 600 mm square and up to about 2 m tall. Common choices are a bedroom or landing cupboard, a utility room, under the stairs or an integral garage. The surveyor looks at your layout and suggests options, including slimline models where space is tight.
Does a heat pump cylinder need servicing?
Yes. An unvented cylinder's safety devices should be checked every year, including the relief valves, the expansion vessel charge and the discharge pipework. This is normally done as part of the annual heat pump service, and it is often a condition of the cylinder manufacturer's warranty. Keep the cylinder paperwork with your heat pump handover documents.
Will I run out of hot water with a heat pump?
Not if the cylinder is sized to how your household uses hot water. Unlike a combi, hot water is stored, so very heavy use, such as several long showers back to back, can use up the stored volume before it reheats. Sizing for your busiest period, and timing reheats sensibly, avoids this for most homes.
Can I keep my existing hot water cylinder with a heat pump?
Usually not. Cylinders designed for boilers have a small coil that cannot transfer heat quickly at heat pump temperatures, so the water would reheat slowly and efficiency would suffer. A heat pump cylinder has a much larger coil. The new cylinder can often go in the same cupboard, though, if there is enough height and floor space.

