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We have an upstairs hot water immersion tank located in a small cupboard that is activated using a manual switch (with red indicator light) in the kitchen down stairs. According to the top of the tank, the immersion heater is rated at 3kW.

I purchasd a 24 hour immersion heater time controller today (Homebase own brand) and would like a little advise as to installation. Firstly the controller switch rating is 3kW, 13A resistive, 5A inductive. As the heater is rated at 3kW, should I be looking for a time controller which is actually rated to operate at greater than 3kW or is it safe to use?

Secondly, the immersion heater is wired directly into a fused switch inside the cupboard. I assume (from the instructions) that the time controller should be wired between the heater and the fused switch inside the cupboard?

Finally I assume once the immersion heater is wired to the time controller for timed activation, the switch in the kitchen needs to be left on at all times?

Apologies if these questions sound naive or stupid, but I'd rather be safe than sorry. Thanks in advance guys.

"Firstly the controller switch rating is 3kW, 13A resistive, 5A inductive. As the heater is rated at 3kW, should I be looking for a time controller which is actually rated to operate at greater than 3kW or is it safe to use?"

What do the instructions say?

"I assume (from the instructions) that the time controller should be wired between the heater and the fused switch inside the cupboard?"

If thats what the instructions say then it's a pretty safe bet.

"I assume once the immersion heater is wired to the time controller for timed activation, the switch in the kitchen needs to be left on at all times?"

Sounds like a safe assumption to me.

Cheers

First of all, I think your new timer switch should be rated highly enough to control your immersion heater. Secondly, since you have an isolator switch in the kitchen, you could simply replace the fused switch in the cupboard by the new timer, provided that the switch in the kitchen is fitted with a 13A fuse. If not you could swap the switch in the kitchen for the one in the cupboard. Finally, once you have installed the timer, you will need to leave the switch in the kitchen turned on to keep the clock in the timer switch running.