Electric shower thermal cut out testing and replacement ( tco )

In this post ill test the thermal cut out it protects the element from over heating, when it trips it does not allow power to go to the main heater element an protects you from overheating hot water or pressure build up in the heater exchanger .

Easy job all you need is a good Multimeter and a Posidrive no2 screwdriver.

The thermal cut out device on an electrical shower is usually at the top of the heater element tank - heat exchanger and it has incoming and outgoing wiring to it .

but its literally only 3 screws Posidrive no2 

If this is tripped the shower will be cold and will be unable to heat the water so main symptom is cold water on all settings.

Buy electric shower parts on Ebay UK here

Need a Multimeter for testing try on Ebay UK here

Test in by continuity testing with the buzzer on Multimeter 

or check to ensure it reads very low ohms or short circuit 

here mine is beeping pit hard to show that on a photo but 

as you can see the ohms reading is 0.000 so very low resistance 

and proves the cutout is still working fine 

Just undo the 3 screws holding it in place and then you can test it out of the shower unit 

or replace .

see video below it was hard to photo removal process 

see a video of this procedure below 

Aftermarket TCO thermal cut out units 

Buy on Ebay UK here 

Thermal overload device