low pressure warning light on/off

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 safety device will 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 if 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.

If the shower is absolutely cold then I think you may have a faulty Thermal Cut Out

A faulty TCO will have no continuity across the two terminals (The black thing on top of the heating tank)

Therefore a good TCO will have power at both connections and a faulty TCO will have power at only one.

(The function of the TCO is, if the water over heats it cuts the power off to the elements)

See Video.

http://www.youtube.com/user/showerdoc#p/u/2/_zi8JbEMYMs

If there is some heat it may be a faulty element in the heating tank (there are two, three in most 10kw showers) you can check them with a multi meter you should have a reading of around 12>18 ohms.

If you have power to the elements and no heat it's probably the elements, no power to the elements then it's probably a micro switch.

If you don’t have a multimeter we sell them at £10 each with a guide on how to use them for checking and testing the various parts of your shower.

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

(so you know if they are dud or not) and lots of other jobs, in short they are well worth the £10.

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