shower mixer not working

[obiwanrobin]

Hi all,

I've just moved into a new massionate, shower mixer tap (in the bath tub) is mixing the water fine as far as you are using the tap, as soon as you pull the knob it only sends either cold or hot water randomly to the shower head. And no matter what you do afterwards it doesn't help its either hot or cold.

My landlord has changed the whole fitting (mixer tap and shower) but the problem still persist. Cold water supply is from the mains and then we have a hot water tank for (on the same floor with a small electric motor) for hot water.

If I remove the shower pipe from the mixer tap then the water (at the top hole that sends to the shower) mixes it perfectly but as soon as you attach the pipe it all goes bad.

Any suggestions ?

Regards
Oli

 

[Newboy]

Possible un-balanced pressure between hot and cold supplies. When the shower hose is disconnected the supplies flow freely, when the hose/head are connected is suspect that the cold is overpowering the hot pressure and on occasions, hot pressure (pumped) overpowering the cold.

Ideally, both the hot and cold supplies should be at the same pressure - both pumped/both mains/both gravity.