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Is it a good idea to fit a timer to my electric boiler?

Boilers generally operate continuously, so that water supply is hot both day and night. By using a timer or the time programming system built into your appliance, you decide when the water should be heated; for example, only at night.

The boiler tank is well insulated and requires little energy to keep the water hot 24 hours a day. Programming the heating times can nevertheless save you a few kWh, with the drawback of having water at maximum temperature only at certain times of the day.

Who would this benefit?

Owners of solar panels

You will benefit most from operating your boiler when the sun is at its hottest, in the middle of the day.

If you are not taking advantage of this energy (the 'reverse meter'), the electricity that you feed back into the network during the day is worth much less than what you take from it in the evening or at night. It is therefore in your best interest to prioritise using your own energy supply.

Consumers on a dual meter will benefit to a lesser extent

If you have a dual meter, you will benefit from heating water at the night rate. However, since the two tariffs are not as different as they used to be, the saving is not huge.

And don't forget to consider your own comfort. If you need a large amount of hot water during the day, the volume of water heated only at night may be insufficient.

Choose your timer carefully to avoid the risk of fire

A boiler often consumes a lot of power: 2,000 to 3,000 watts (W). Your timer must be equipped for this purpose, otherwise there is a risk of fire!

How can I calculate the current-carrying capability?

Check the packaging of the timer to see if it can tolerate the power of your boiler.  This is usually expressed as a 'current-carrying capability', e.g. 10 amps (A). A quick calculation will tell you if that's enough. Let's say you have a 3,000 W boiler at 230 volts (V).

boiler power / voltage = minimum number of amps your timer must be able to tolerate.
3 000 W / 230 V = 13 A.

In this case, the current-carrying capability of your timer must therefore be greater than 13 A.

How do I set my timer?

Two-phase boiler: you can install it yourself

Is your boiler fitted with a plug? Great! You probably have a two-phase boiler.

Connecting a timer to it is as easy as pie, using a device that plugs into an ordinary electrical outlet and has a socket for the boiler.

Three-phase boiler: call an electrician

A three-phase boiler, on the other hand, is not fitted with a plug, but is connected directly to your distribution board.

Connecting a timer to this type of boiler requires some technical expertise. Ask an electrician to install a timer on your distribution board.


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