News, Views & Reviews on Domestic Central Heating, Boiler & Renewable Energy


Get Free, No Obligation Boiler Quotes

Insulating Your Hot Water Tank

Insulate Your Hot Water Tank

Insulating your hot water tank is a simple and cost effective way of keeping your energy bills down and reducing carbon dioxide emissions. The insulation will keep your water hot for longer as it prevents heat escaping from the tank. By insulating the water tank with a thick jacket (sometimes referred to as a lagging jacket), you can cut heat loss by up to 75% and the cost can be recouped in less than a year. It’s also an environmentally friendly option saving around 160kg per year in carbon dioxide emissions.

Insulation jackets can be purchased from any good DIY store from around £10 and can save you around £10 – 15 a year on heating costs.

The jackets come ready made and fit a variety of standard sizes. Use a tape measure to calculate the height and girth of the tank to ensure you buy one which fits neatly. The thickness of the jacket should be at least 80mm. If you already have insulation for your hot water tank, check to make sure it’s no thinner than this. If it is, you can add a second jacket or replace it completely. When buying a new jacket, ensure it conforms to British Safety Standards BS 5615 (1985).

Fitting the jacket is a straightforward task and can be done easily yourself without the need for a skilled tradesman. The jacket is made up of several segments held together with a cord, which ties over the top of the tank. Straps are used to keep the jacket fitted securely but shouldn’t be tied too tightly.

Before fitting the jacket, turn off any heating and allow the tank to cool. Follow the manufacturer’s instructions to fit the insulation correctly. It’s important not to apply too much pressure when smoothing down the jacket as this can cause the insulation to be less effective.

If your hot water tank is in an airing cupboard, the insulation will reduce the amount of heat circulating. If you want to allow some heat through, tie the segments of the jacket slightly looser, with a few gaps. Otherwise the segments should be overlapped to prevent heat escaping.

If you’re living in a newly built house or have just purchased a new hot water tank, there is no need to fit an insulating jacket, as new hot water tanks come with foam insulation already fitted. This new method is much more effective as a means of insulation.