Immersor stat fault

[Welsh_sparky_21]

Thermal cut out kept going on immersor stat so changed the stat over, now the new one keeps having the same issue. Any ideas on what it could be?? Could be another faulty stat but I highly doubt that

 

[telectrix]

have you checked the element? continuity and IR?

 

[DJAndy]

First one of these I dealt with on my own the tenants had turned up the thermostats on both elements. The boost thermostat was high enough to trip the thermal cut out on the night time element but only if the tenants boosted two hours in a row.

I thought I was going mad.

 

[brianmoooore]

Probably not applicable, but is there another method of heating the cylinder?
Many of my customers have Rayburns or woodburners also heating the cylinder, When these safety cut outs were first introduced, I was plagued by callouts to reset them, as the alternative source regularly heated the water to a temperature that would trip it out.
Not so many calls in recent years. I don't know if that's because the cut out temp. spec. has increased (doubt it), customers have learnt not to let the water get too hot, or they've just learnt to reset themselves (probably).