Reality Check · August 2026
Cylinders, Buffers & Low-Loss Headers for Heat Pumps
Public prices for the hydraulic package that sits inside a proper heat pump system, and how the calculator already accounts for them.
Quick Answer
A proper heat-pump cylinder is not the same as a standard boiler cylinder. It needs a larger coil so it can heat the water from the lower temperatures a heat pump produces. Public prices for a heat-pump-ready cylinder currently sit around £900–£1,800 for a standalone unit and £1,500–£2,800 for a pre-plumbed version. Buffers and low-loss headers add another £150–£700 for typical sizes.
These components form part of the equipment package already inside the full installed bands the calculator uses. The calculator does not use the absolute cheapest possible cylinder; it uses a realistic heat-pump-ready unit that will actually work with the system and meet MCS requirements. That is why the figures sit where they do.
What public prices show
| Component | Typical public range | Notes |
|---|---|---|
| Heat-pump cylinder (standalone 200–300 L) | £900–£1,800 | Larger coil than a standard boiler cylinder |
| Pre-plumbed heat-pump cylinder | £1,500–£2,800 | Often includes pump, valves, expansion vessel |
| Cylinder + integrated buffer | £1,700–£2,800+ | Combined packages from several makers |
| Buffer tank or low-loss header | £150–£700 | Common sizes 30–100 L or compact headers |
Grant, Vaillant, Samsung, Gledhill, Joule and others all publish heat-pump-ready options. Pre-plumbed versions cost more but reduce time on site.
Why these components matter
A heat pump runs at lower flow temperatures than a gas boiler. A standard cylinder coil is sized for hotter water and will not recover the hot water store quickly enough. A heat-pump-ready cylinder has a much larger coil surface area so it can transfer heat effectively at the lower temperatures.
A buffer or low-loss header separates the primary circuit (the heat pump) from the secondary circuits (radiators or underfloor). This keeps the flow rate through the heat pump stable even when zones open and close. Many manufacturers recommend or require some form of hydraulic separation, especially on larger or multi-zone systems.
These are not optional extras on a proper install. They are part of making the system work reliably and efficiently.
How the calculator treats them
The full installed planning bands already include a realistic heat-pump-ready cylinder and the hydraulic components that are commonly required. They do not assume the cheapest bare cylinder or a system with no buffer or header.
The public prices above form the foundation. The calculator builds the complete figure from them so the planning number includes the cylinder and hydraulic package that will actually work with a heat pump in a Devon or Cornwall home. That is why the bands sit where they do.
South West notes
Space for a larger cylinder or a separate buffer can be tight in older terraces and cottages. Slimline cylinders and combined cylinder-plus-buffer units help. Access for a larger vessel into a first-floor airing cupboard or loft can also add time and cost on some properties. The survey confirms what will fit and what is required.
See the full planning band for your home
The free heat pump Passport already includes a realistic cylinder and hydraulic package inside the installed figures. No obligation. Every submission is personally reviewed.
Start heat pump Passport →Frequently asked questions
Do I need a special cylinder for a heat pump?
Yes. A heat-pump-ready cylinder has a larger coil so it can heat the water from the lower temperatures a heat pump produces. A standard boiler cylinder will not recover quickly enough.
How much does a heat pump cylinder cost?
Public prices for a heat-pump-ready cylinder currently sit around £900–£1,800 for a standalone unit and £1,500–£2,800 for a pre-plumbed version. Buffers and low-loss headers add another £150–£700 for typical sizes.
Is a buffer always required?
Not always. Some systems can run without one if the heat pump and emitters are well matched. Many manufacturers recommend or require hydraulic separation on larger or multi-zone systems. The design survey decides.