Night Storage Heaters – How They Work

Night storage heaters are designed to enable you to heat your home steadily throughout the day by using the cheaper nighttime electric rate to create the heat.

How they work :-

Storage heaters work by heating up bricks inside the heater during off peak hours, when electricity is cheaper than the daytime rate. The bricks then release the heat throughout the day to give you a steady heat.

To enable this to happen you need to have a dual rate electric meter. You will know if you have one if your meter shows 2 readings, sometimes labelled R1 and R2, or the display regularly switches between 2 sets of figures (every few seconds).

The meter switches automatically between the rates at 00:00-07:00, , Greenwich Mean Time – hence the name ‘Economy 7’ because the cheaper electric runs for 7 hours.

During British Summer Time the cheap rate automatically adjusts to 1am – 8am. You do not have to change anything yourself.

(Another common rate is ‘Economy 10’ which usually runs between 00:00 and 05:00, 13:00-16:00 + 20:00-22:00)

If you do not have a dual rate meter then you may be able to have one fitted if you call your electricity supplier.

How to use them:

Because they heat up through the night they need to be switched on the day before!

They can be switched on at any time the day before because they won’t start heating up until the electric supply automatically switches over at 00:00/01:00 so you don’t have to worry about turning it off the next day. If you want heat through the following day just leave it switched on, if not turn it off. Checking the weather forecast every evening, especially during the Spring and Autumn, will help you to decide.

There are usually 2 very basic controls on a night storage heater:-

Input control – this controls how much the bricks are heated up overnight. The hotter the bricks the more heat they will have for the next day.
Output control – this operates a flap that covers a vent in the heater – the more you open the flap the more the heat can come out.

Boost control:

If the heater has a ‘boost control’ feature it also has a heating element that is wired to the daytime electric supply. This means that you can turn it on at any time for an extra heating boost– useful on a cold evening when the main heating bricks have cooled down.

Immersion water tanks:

If you have ‘Economy 7 or 10’ then your water heater is likely to work in the same way:-

The main tank will heat up overnight, using the cheaper electric, to give you a full tank of hot water by the morning.
The ‘boost’ is there so that you can top up the heat, if by the end of the day, you need a bit more hot water. Do not leave the boost on as a matter of course, it will prove to be very expensive.