A: This cuts the power off to one element if the water temperature gets too high.
However...........
The things to check first are.
1 That the main valve coming into your house is fully open.
2 Then check that the valve on the line to the shower is fully open.
If these valves are not fully open then there may not be enough water
getting to your shower to cool it properly the overheat safety device will turn
the power off until it cools Then it all starts again
Make sure that the shower head is clean and clear, that the hose isn’t kinked (this can happen just behind the hand set where it is difficult to see) also check the inside of the hose although it can look OK on the outside it could have collapsed internally
The other possibility is a faulty flow/stabilizer valve not allowing the correct amount of water into the shower.
Answered 285 days ago | The doc