Well it sounds like you have a thermostat valve, most of the time when
they need replacing is generally when they leak and cause constant
dripping, is yours wall mounted or the bedded type that is on your
bath, they tend to have a filter where they connect to the water under
the bath but I would recommend a plumber to deal with that, if it is
the valve itself that is gone generally they drip and quite expensive
to replace, you have got to know the name of the mixer to obtain the
new valve there is loads of different makes, some of them are easy to
replace but some of them are a mission.

wrote:
wrote:
If you don't have a thermostat valve, but only a manual hot and cold
taps it would be probably difference in water pressures.

Try turning on the hot only and gradually feeding in the cold.

This is the sort of valve that starts out cold and gets hotter as you
turn it counter-clockwise. There's only one knob, unfortunately. I'll
have to look and see what model it is. I can probably find a
replacement at Home Depot or Lowe's, if that's the problem.

I've never taken one of these apart before. Is this a pretty easy job
or can it be tricky?