Overheat protection for immersion heater

[interesting100]

Hi
is there any kind of system that will turn off an immersion heater if the tank water gets too hot - ie if the immersion heater's own thermostat failed and it stayed on all the time ?
thanks

 

[neily01]

New immersion stats have a built in overheat cut off. Fairly standard now 7" or 18" long

 

[interesting100]

Can they go wrong ?

 

[lame plumber]

designed to fail safe ie to hot turn off

 

[stevetheplumber]

everything and anything can go wrong but most electrical stuff is pretty well tested nowdays so the probability is no it wont go wrong