i dont have a call to do much with immersion heaters these days, but came accross something odd today. custommer complaining of hot water being red hot. i suggested turning the thermostat on the emmersion down ( no other form of indirect heat to tank, just electric). so duly tried that after testing that the thermostat worked. called again a few days later to say still red hot. decided to change thermostate. still the same. removed emmersion and checked not scaled over, all was ok. resistance reading of emmersion was also ok. all replaced. again another thermostat fitted (thank god they are only a few pounds!) well went back today and the over heat trip had gone. so three in a row not performing as expected.
the tank itself is a early 1980's tank, not scaled up and emmersion in good order. the only obvious fault with it is that it had been fitted with a 11" emmersion instead of a 27", which would fit.
only thing i can think is that the new thermostates are slightly smaller than the original fitting, so there is not enough contact between the dry pocket and its outer sleeve. this sounds inprobable to me. has anyone had problems like this?
the tank itself is a early 1980's tank, not scaled up and emmersion in good order. the only obvious fault with it is that it had been fitted with a 11" emmersion instead of a 27", which would fit.
only thing i can think is that the new thermostates are slightly smaller than the original fitting, so there is not enough contact between the dry pocket and its outer sleeve. this sounds inprobable to me. has anyone had problems like this?