Point of use water heaters

Electric point-of-use water heaters eliminate the problem of long pipe runs by being near each hot water outlet. The cost of the most basic ones for small hand basins starts at around £300 + installation.

If you have a hot water storage tank supplying just a few taps, depending on the circumstances, it may be more efficient to switch to a electric point-of-use water heater:

• if the tank is old and could fail soon

• if you are switching to a heat pump, radiant or contact heating, or combining these with running your gas boiler less

• if you just need small amounts of hot water or struggle to predict demand

• with hot water from a condensing boiler, if the tank is the only reason to run the boiler on a high temperature

• if the building has a tank and is lightly occupied, making Legionella protection a major part of the gas use

• if it’s a long way between the tank and the taps, especially if the pipes are hard to insulate

There are two types - ones with tanks and tankless ones that heat the water “on demand”. Tankless ones have to be very near the tap and are more convenient for the building management but might not support the flow rates required for thirsty appliances like showers and dishwashers. Both types require some maintenance against limescale, especially in hard water areas, but the tankless ones are more susceptible.

You will need to consider running costs as well in making your decision, since electricity is currently more expensive than gas. Point-of-use water heaters typically draw 3-7 kW when they are in use. One rule of thumb we’ve seen but can’t verify is that tankless is more expensive to run than something with a 10L tank, but less expensive than running a larger tank.