immersion heater


10 Aug 2004
Reaction score
United Kingdom
hows do i know if the element has gone or the thermostat.

if the thermostat is knackered then is the immersion heater on all the time or off all the time ?

Sponsored Links
Disconnect from the mains and measure the resistance through the thermostat and the element seperately, use a multimeter. Only do this if you know what you are doing.
If the thermostst is gone it can be perm or perm off, some stats now have internal resetable overheat button , you can check using multimeter the resistance of the element should be R (ohms)= V 230volts / I 13Amps = 17.60 ohms with cable wires disconnected across live and neural.

Generally if you turn on the immersion and it blows the fuse its the element, this can be tested using an insulation resistance meter (400v) measured live to earth (cylinder) with the wires diconnected. If the goes it overheats or does not heat up at all. Check for votage to stat live to neutral. (check polarity, live is on stat)

:!: Always remove fuse when testing, easy to knock on isolation switch,
Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local