Insulating a hot water tank to 80mm could save around £45 a year in the UK, according to the Energy Saving Trust, as hot water accounts for around 11% of the average UK energy bill.
With energy bills rising again, households could save money by making a few simple changes to how they heat their water. The device or appliance to check is the hot water tank, usually found in an airing cupboard. It stores the hot water used for showers, baths and taps. Some tanks are heated by a gas boiler, while others use an electric heater fitted inside the tank.
Simple insulation savings
While many Brits focus on turning down the thermostat or switching off lights, heating water also adds to household costs. One simple way to save is to make sure the hot water tank is properly insulated. This helps keep the water warm for longer, so less heat is wasted. Insulating the pipes connected to the tank can also help.
The Energy Saving Trust said: "Lagging water tanks reduces the amount of heat lost through the tank. This means the water stays warm for longer, so less energy is wasted. Insulating your hot water cylinder is one of the easiest ways to save energy and money."
Electric heaters and solar panels
Households with an electric water heater could also save by checking whether their electricity tariff offers cheaper rates overnight. If it does, they may be able to set the heater to warm the water during those cheaper hours. Check your tariff before changing the settings, as using electricity at the wrong time could cost more.
Homes with solar panels may be able to use spare electricity generated during the day to heat their water, reducing the amount they need to buy from their energy supplier. There are also simple ways to use less hot water, such as taking shorter showers, fixing dripping hot taps and avoiding running the hot tap when it is not needed.
Price cap and alternatives
Ofgem's energy price cap rose by 4% on October 1, increasing the typical annual bill for a household using gas and electricity. Households on standard variable tariffs are paying an average 26.32p per unit of electricity and 7.97p per unit of gas. Electricity VAT has also been removed temporarily for households covered by the price cap between October 2026 and March 2027.
For households thinking about replacing their water heater, a heat pump water heater is another option. It uses warmth from the surrounding air to heat water and can use less electricity than a traditional electric heater. However, buying and installing one can be expensive, so it is worth comparing the upfront cost with the potential savings.
Not every home has a hot water tank. Many homes with a combination boiler heat water as it is needed, so advice about tank insulation will not apply to them. For renters or anyone unable to replace their equipment, using less hot water and checking that any tank and pipes are properly insulated are simple places to start.
