Thermostatic shower not very hot

22 Feb 2007
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United Kingdom
I fitted a thermostatic mixer shower about six months ago and now that cooler weather is here i am finding that water is not getting hot enough even when shower is turned fully to hot position. Water is heated by a combi boiler which is on maximum temperature and all other taps are very hot including bath taps. Would putting an isolation valve on cold supply upto shower and reducing cold water flow do anything? Any advice appreciated....
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no because it's a thermostatic shower.

try turnning the temp from fully hot to fully cold a few times.
as people tend to leave the temp in one place the cartridge can become stuck in one place and operateing them fully keeps the cartridge free.

if it can't be freed new cartridge.

or the mixer may have the max temp adjuster set to low
I've also got a thermostatic shower that has gone cold. It's only a couple of months old. As per bashersmith's worcester bosch 30CDi has water temp at max and all other taps are roasting.

I did a bucket fill test for the bath taps - cold water supply 8.0 litres in 30 secs. Hot water was about 4.5 litres.

So I'm trying to work out if I need to reduce the flow or reduce the pressure - or is this the same thing? and how to go about this.

Last night I tried turning the cold water isolation valve on the cold water feed to partially off - with a result that the cold water bucket fill reduced to just below about 5 litres. The shower water temp was abit better, but the next morning (I assume when cold water was bit colder) the temp was luke warm again.

Any thoughts welcome.
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