Heat Pump Hot Water Cylinder Cost UK 2026
Every heat pump installation needs a hot water cylinder, typically costing £800-£1,400 installed for a standard 200-litre model. This component is essential because heat pumps heat water gradually rather than on demand -- but it also means mains-pressure hot water and the end of lukewarm trickles from a gravity-fed system.
The cylinder is normally included in the overall heat pump installation quote. For total installation prices, see our heat pump cost guide.
See your total installation cost including cylinder
Use the free calculatorCylinder cost is included in total estimates.
How Much Does a Cylinder Cost?
| Size | Unit Cost | Installed Cost |
|---|---|---|
| 150 litres | £400-£800 | £600-£1,000 |
| 200 litres | £550-£1,100 | £800-£1,400 |
| 250 litres | £700-£1,300 | £1,100-£1,800 |
| 300 litres | £900-£1,600 | £1,400-£2,200 |
Why Heat Pumps Need a Specific Type of Cylinder
Heat pump cylinders differ from standard boiler cylinders in three key ways: larger coil surface area (3-5m2 vs 1-2m2) for efficient heat transfer at lower temperatures, better insulation (50-100mm polyurethane foam), and immersion heater backup for legionella pasteurisation. See our installation guide for more on system components.
What Size Cylinder Do You Need?
Popular Cylinder Brands
Budget (£400-£700): Kingspan Ultrasteel Plus, Gledhill Stainless Lite Plus, Telford Tempest. Mid-range (£700-£1,100): Joule Cyclone, OSO Accu. Premium (£1,000-£1,500+): Vaillant uniSTOR, Mitsubishi Ecodan cylinder. Manufacturer-branded cylinders are not always necessary -- a quality third-party cylinder works with any heat pump brand.
Can You Reuse Your Existing Cylinder?
Possibly, if it has at least 150L capacity, 3m2+ coil surface area, good condition, and an immersion heater. In practice, most existing cylinders are too small or have inadequate coils.
Get quotes that include the right cylinder for your household
Get free quotesInstallers will assess your cylinder needs during the survey.
Vented vs Unvented Cylinders
Most modern heat pump installations use unvented cylinders (£500-£1,400) for mains-pressure hot water. Vented cylinders (£300-£800) are cheaper but require a loft tank and provide lower water pressure.
Running Cost of the Cylinder
Total hot water costs with a heat pump: typically £300-£450/year for a family of 3-4. Comparable to or slightly less than gas. If your home has solar panels, heating the cylinder during peak generation hours can further reduce costs.
Frequently Asked Questions
How much does a hot water cylinder cost for a heat pump?
A 200L cylinder costs £800-£1,400 installed. Included in the overall quote.
Can I use a normal cylinder?
Only if it meets coil and capacity requirements. Most standard cylinders do not.
What size for a four-person household?
200-250 litres. Our calculator helps estimate needs.
Do I need a cylinder if I have a combi boiler now?
Yes. Finding space for the cylinder is one of the main combi-to-heat-pump considerations.
Will I run out of hot water?
If correctly sized, no. A 200L cylinder provides enough for 2-3 baths before reheating. See our running costs guide for more.
Get a complete quote including the right cylinder for your home
Get free quotes nowQuotes include cylinder, heat pump, installation, and BUS grant application.
About this guide: This article covers the cylinder component of heat pump installation costs. The hot water cylinder is essential for air source heat pump systems and is included in the BUS grant eligible costs. Heating the cylinder with solar-generated electricity during daytime hours maximises efficiency.