Triton T80si Pumped

I think you have twofaults.....First the hot cold problem

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.

Also as it is a Triton have a look at the outlet TCO

The outlet Thermal Cut Out this is a black disk with two wires going toit and it is mounted on the out let pipe (The bit between the heating tank andthe hose)
Examine the connections closely if you see any discoloration / signs ofoverheating then the TCO needs replaced.

The fact that it is cutting out.

It may be your solenoid valve, you can check it if you havea multi meter, you should have a reading of at least k3.5 ohms, across the twoterminals any less and you need a new valve. (Check the valve in the failedstate.) (When it has stopped working!)

If there is power getting to the solenoid and it is notoperating then there is a good chance that you have a faulty solenoid.

http://www.youtube.com/watch?v=NzJjzWqxesc

The videois intended as a guide and does not cover every shower.

If you don’t have a multimeter  we sell them  with a guide on how to use them for checkingand testing the various parts of your shower.

Apart from helping to fix your shower, they are reallyuseful for checking you have a power supply to appliances, for checking fusesand letting you know much power you have left in batteries

(So you will know if they are good or not) and lots of otherjobs, in short they are well worth a few pounds

http://www.showerdoc.com/installation/electrical-products/SKYTRO-600-005-Digital-Multi-Tester