Immersion heater

[STI]

Hi how can i tell if my immersion heater is up to the current requirements regarding disconnection of supply and prevention of boiling water should the thermostat fail. My thermostat has a dial with a temperature setting on it but does this mean it has got the safety cut out. It looks the same as every other thermostat i have seen but how can i be sure.
Is it the thermostat that has this faciltiy or it the element.?

Thanks

 

[Lectrician]

On some a second reset button is obvious, or a second device in line with the thermostat.

For the price of a replacement (check length), and it being a dry job to do, I would just swap it.

http://www.tlc-direct.co.uk/Products/IHST7slashC.html

 

[electronicsuk]

As above, although if the thermostat has a combined overheat cutout, there will usually be a small reset button to indicate this.