electric shower doesn't run cold - - advice please!

[Andrea]

I wonder if anyone can give me any advice.

I recently moved into a house and found that the electric shower cycled between hot and cold. Thinking the shower faulty I replaced it with a Gainsborough 8.5kW shower. Unfortunately, there still seems to be a problem. The water pressure is fine (as far as electric showers go) but I seem to be unable to get it to run cold. Even when I run it on low power and minimum on the dial, it still puts out water which is slightly too warm for comfort.

Does anyone have any idea what the cause might be? (I am confident I have connected it the cold water supply, it was a take it out of the box and wire it in sort of affair).

Thanks.

[shaun]

Try taking the front off the shower (making sure it's isolated from the mains), turn the temperature dial (on the now disconnected part) up slightly and then refit the front. You should now be able to turn the temperature down a bit more than you could before.

[David W.E. Roberts]

Just to confirm; most electric showers used to have 4 settings. High Low Cold Off

If yours has a 'cold' setting have you run it on this for a while and got really cold water out of it?

How long are you running the shower for?

One likely reason for over temperature water is that it is arriving at the shower already warm. Just wondering if you are, after all, connected to the hot water or if the cold water feed runs alongside a hot pipe and is thus being heated before it gets to the shower.

Alternatively the water pressure may be too low - cycling between cold and very hot is usually a sign that the water is overheating, the thermal cutout is turning the heater off, the shower cools down then starts heating again.

Variations in the water pressure could also do this - is anyone else using cold water whilst you are showering (including dishwasher or washing machine) or are you sharing a water supply (flat, etc.) with others?

Finally, did you throw away the old shower? It could be that it is O.K. and good for a spare or other project.

HTH Dave R

P.S. check that your mains cold water stop c*ck is turned fully on in the house - I was advised to open any tap like this fully then turn it back 1/4 turn to reduce the chance of it jamming open.

[Andrea]

Thanks.

The temperature dial on the front is one of these strange ones which doesn't have a stop, i.e. turns continuously until it reaches the stop on the dial in the box itself.

[BigWallop]

Thanks,

The shower only has three settings: High Low Off

Hi Andrea,

From your description, I get the feeling we're talking stuck switch here. Even when the shower is on its LOW setting, you get hot and not warm water ? Then if you put the shower to the HIGH setting, the temperature doesn't change ?

If this is the symptoms, then the micro switches in the unit have stuck closed (electrically welded themselves together). Replaceing them is no big deal, and is very cheap indeed. Turn off the power to the shower at the fuse board. Open the front of the unit and have a look inside, you should see where the selector knob goes onto a spindle and controls two little micro switches:

which make the heating elements work.

Have a look at the spare parts pages here:

for the bits you need. Or you can go to your nearest electronic store and ask for two 240 Vac 20 Amp MicroSwitches.

(pronounced two forty volt A.C. twenty amp micro-switches)

Good luck with it.