Most heat pump cylinders are unvented, meaning they run at mains water pressure and give strong flow from every tap without a cold water tank in the loft. Unvented cylinders have safety controls that must be fitted and checked by someone qualified to work on them. We size the cylinder from your household and bathrooms, confirm your mains water supply can support it, and plan the space, pipework and discharge route at the survey.
Discharge pipe routes are planned at the survey so a County Londonderry cylinder can drain safely to the outside. Older houses in County Londonderry with loft tanks can usually have them removed when an unvented cylinder is fitted. Cylinder sizes for County Londonderry homes are based on the people living there and the bathrooms in daily use.
Who it suits
- Every air-to-water heat pump installation, whatever the existing boiler
- Homes replacing a combi boiler that need space found for a cylinder
- 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
Grants and rules for heat pumps in Northern Ireland
Northern Ireland does not have a dedicated heat pump grant for homeowners at present, and the Boiler Upgrade Scheme does not apply here. Heat pumps have sometimes been funded through the Northern Ireland Sustainable Energy Programme, so it is worth checking what is open when you enquire about a home in County Londonderry.
There is no VAT on installing a heat pump in Northern Ireland until 31 March 2027, the same as in Great Britain. Planning and building control here follow Northern Ireland's own rules, so the survey checks the unit position against them.
Heat pump hot water cylinders prices in County Londonderry
Here are typical prices for heat pump hot water cylinders in County Londonderry, 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) | £1,150–£2,150 |
Supplied and fitted, inc VAT. Included in every full system price.
Towns we cover in County Londonderry
We cover 7 towns in County Londonderry for heat pump hot water cylinders. Each links to local guide prices and the grant position for Northern Ireland.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Derry/Londonderry | BT48 | Limavady | 7 h 10 min |
| Coleraine | BT52 | Portstewart | 7 h 08 min |
| Dungiven | BT47 | Limavady | 7 h 11 min |
| Limavady | BT49 | Dungiven | 7 h 09 min |
| Maghera | BT46 | Magherafelt | 7 h 12 min |
| Magherafelt | BT45 | Maghera | 7 h 13 min |
| Portstewart | BT55 | Coleraine | 7 h 08 min |
Heat pump hot water cylinders questions
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.
How much does a heat pump cylinder cost?
A heat pump hot water cylinder has a guide price of £1,200–£2,200, installed and including VAT. In a full heat pump installation the cylinder is already included in the system guide price, so this figure mainly applies where a cylinder is replaced on its own. Capacity, coil design and the pipework needed affect where your price sits.
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.
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.