Glenn Proctor wrote:
Hi

We've got an electric shower. It's made by Aqualisa, and (I'm not sure
of the correct term here) it just pumps the water - it doesn't do any
heating. There's a temperature control knob on the front as well as one
for adjusting the flow.

It's about 3 years old and has always been fine, however over the last
few months we've noticed it's not quite as hot as it used to be. Even on
the maximum temerature setting, it's not as hot as the water coming out
of the taps. I've confirmed this using a thermometer.

Any suggestions? I'm aware that electric showers have temperature
limiters in them, but that wouldn't explain why it used to be OK, but
isn't now.

We've had some plumbing done elsewhere in the house, so the mains
stopcock's been off and on a few times. The only thing I can think of is
that the cold water pressure coming into the shower is too high, and
there's not enough hot water for it to "keep up" - could this be the
reason?

The cold supply should probably be off a separate tapping on the cold
tank in the roof (though some shower mixers can cope with mains cold and
gravity hot). Could be filter on the hot inlet to the shower getting
blocked: this'll probably be in the pipe connecting into the mixer (i.e.
impossible to get at :-).

Or (assuming it's thermostatic) the thermostatic mechanism could be
getting out of kilter.

You could let the hot water go cold and check whether you get a good
_flow_ from the mixer, set to max temperature. If you don't that'd
suggest blocked filters, if you do it's likely to be the thermostatic
mechanism.

You should be able to take it apart and clean it (though you may find
O-rings don't seal well when you put it back together again) and you
should be able to get a new themostatic mechanism innards for it from
Aqualisa (which I hope would include any O-rings you need to replace in
doing so).