Immersion heaters and thermostats

25 Feb 2004
Reaction score
United Kingdom
I wonder if any of you can tell me a simple test to check whether my immersion heater element or the thermostat has failed.

I'm not getting nay hot water and the only means I have to heat water is using the immersion heater fitted into the cylinder.

I have a multimeter so could measure the voltage but am not sure how I'd know if either the element or the thermostat are to blame.

Many thanks in advance,

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Turn it off - take the fuse out.
Then use the continuity setting on the meter - or low Ohms range.

Between the two screws on the thermostat should be nearly 0 ohms if the water's cold, and between the two rods poking up from the heating element should be about 20 Ohms.

(Obviously you can look for 230V if you feel confident about that.)

Thanks for the reply. Just to clarify I'm not sure about the Ohms setting on my meter so I'd be happier measuring the voltage.

I'm not sure how to test each part individually though.

Once again many thanks,


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