Hot-water cylinder insulation
If a rented home has a hot-water cylinder with a thin jacket or none at all, insulating it is one of the cheapest EPC gains there is — and it cuts the heat lost while the tank just sits there.
What it is
A close-fitting 80mm insulating jacket over the hot-water cylinder, plus lagging on the exposed pipework, so the tank holds its heat instead of warming the airing cupboard. Where a cylinder has only thin factory foam we top it up; where it has an old thin jacket we replace it.
Why it matters for 2030
The EPC scores cylinder insulation directly, and a well-insulated cylinder is a low-cost, quick point-gain that pairs naturally with heating-control and heat-pump work. It also cuts the tenant's water-heating bill.
Which homes suit it
Any property with a vented or unvented hot-water cylinder that is poorly insulated — common in older systems. Combi-boiler homes with no cylinder do not need it, and we will tell you so.
Grants that apply
Cylinder insulation is an eligible measure under the Warm Homes: Local Grant and ECO4 when fitted with other work, and zero-rated for VAT until 31 March 2027.
How we do it
We fit a British Standard jacket and pipe lagging, check the cylinder thermostat, and record it for the EPC — a quick, low-cost visit usually bundled with the rest of the plan.
Common questions
How much does it save?
A good jacket cuts the standing heat loss from the cylinder substantially, paying for itself quickly on the water-heating bill.
Do I need it with a combi boiler?
No — combi homes have no stored cylinder, so there is nothing to insulate.
Is it worth doing on its own?
It is cheap enough to be worth it, but it gives the most bundled with other measures.
Will it get in the way of the immersion heater?
No, the jacket is cut around the immersion and controls so they stay accessible.
Related: heating controls · air source heat pumps · draught-proofing