A: 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.
Do any of the lights on the cover come on? If they do have a look below
It could be a faulty relay board or faulty flow valve there is no way to know for sure.
However our experience is, if the service light comes on then it’s most likely to be a faulty relay board.
If it’s low pressure light then it’s most likely to be the flow valve.
No lights at all then probably the relay board
If you are unsure start with the relay board, this is the more common fault.
On a few occasions you may need both, if you need to be certain then order both!
No lights at all then you may have a faulty transformer.
You can check this, there is a white plug at the top of the relay board, the blue and red wires are mains
and should have 240v the black wires are from the transformer and should have 12v AC
If the transformer is OK once again, start with the relay board.
George
Fitting Board and valve.
Obviously turn the power and water off .
Changing the board is fairly straight forward just take notes and photos of where all the cables and plugs go as you dismantle then it should be easy to reverse the procedure.
To change the flow valve you have to remove the ‘U’ clamp on the inlet and the screw at the foot of the heating tank there is then a small tab to the right of the heating tank this is a clip you need to pull this forward to release the hook you may need to use a screwdriver or pliers to flick it forward.
The tank and valve should then pull forward enough to be able to separate them, then remove the plug from the circuit board.
Fit the two new ‘O’ rings supplied and then push the tank and valve together offer the assembly back up and into place, refit the ‘U’ clamp and the screw at the bottom of the tank and make sure that the hook clippie thing is firmly pushed back into place.
Turn on water and test also check the earth wire that runs across the top of the flow valve is clear of the purge button and remember to press the purge button for 15secs to allow the heating tank to refill.
George