Intermittent fault

Thanks for the furtherinformation your shower is clearly suffering from not enough water passingthrough it to cool it.

The reply starts off the sameas be ore but with some further checks.

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 devicewill turn
the power off until it cools Then it all starts again

Make sure that the shower headis clean and clear, that the hose isn’t kinked (this can happen just behind thehand set where it is difficult to see) also check the inside of the hosealthough it can look OK on the outside it could have collapsed internally

The other possibility is a faulty flow/stabilizer valve not allowingthe correct amount of water into the shower.

A ruff check is to remove the shower head turn temperature control tofully hot the water coming out of the hose should be a bit more than a dribblethen turn to fully cold and it should be coming out at full flow.

If there is not much difference between the two then you could have afaulty flow valve.

Carry out this check after you check the inlet valves.

You could give your local water authority a ring an ask themwhat your water pressure should be, they will probably say that the supply aminimum of 1bar (the minimum required to operate a shower)however pressthem and ask what it is likely to be first thing in the morning (when everybodyis showering)

They could have the pressure turned down because they areworking on the main, or because there is a burst pipe some where and they haveturned the pressure down to try to save water, or the pressure maybe low justbecause there is a burst pipe somewhere, that hasn’t been discovered yet!