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Tanks and pipes insulation

Insulating your hot water cylinder is one of the simplest and easiest ways to save energy and money. Fitting a British Standard 'jacket' around your cylinder will cut heat loss by over 75%. If you already have a jacket fitted, check that it's at least 75mm thick. If not, it's well worth treating your old cylinder to a new winter coat.

How tank and pipe insulation works

Both tank and pipe insulation keep your water hotter for longer by reducing the amount of heat that escapes.

The savings

A new, 75mm thick hot water cylinder jacket will save you around £35 per year. The jackets themselves cost less than half that, meaning that you can reclaim your initial cost in less than 6 months. Insulation for hot water pipes will cost around £10 and can save you around £10 a year, which means you should recover the cost of fitting within a year.

You'll be saving about 190kg of carbon dioxide (CO₂) when you fit a British standard hot water cylinder jacket and around 60kg of CO₂ with pipe insulation.

The following table gives approximate costs, savings and paybacks for hot water cylinder jackets and pipe insulation:

	Hot water tank jacket	Primary pipe insulation
Annual saving per year (£)	Around £35	Around £10
DIY cost	Around £12	Around £10
DIY payback	Less than 6 months	Around 1 year
CO ₂ saving per year	Around 190kg	Around 60kg

How the savings add up

If everyone in the UK topped up their tank insulation to the full recommended thickness of 75mm, there would be enough CO₂ saved per year to fill 5.3 million double decker buses.

A hot water jacket costs around £12.

How it is installed

A hot water cylinder jacket costs around £12. Fitting a jacket to a hot water cylinder is a straight forward DIY job. Fitting insulation to pipes is easy if the pipes are accessible and will cost around £10. Professional help may be required to fit insulation to harder to reach pipework, which would incur extra cost.

What to do next

If you have other questions why not visit our FAQ section. If you still have other questions why not call your local Energy Saving Trust advice centre on 0800 512 012 for free, impartial advice on saving energy in your home.

Savings assumptions