mixer shower runs cold-combi boiler

[allan mills]

Hi- Can any1 solve this problem? I have a thermostatic mixer shower. It runs off a combi maxi boiler. cold pressure is v good- so is the hot. But it comes out only mildy warm- virtually cold.
when i turn on the cold basin tap the mixer seems to get hotter- is this a problem with the thermostat? or is it an unequal pressure problem?
I cant access the shower pipes- apart from lifting up the floor tiles ):
Would a pressure reducing valve on the cold feed after the main stop cock solve this?
Cos its doin me ead in!

Please help
Allan

 

[gas4you]

Could be a pressure problem. Did the MI's for the shower ask for non-return valves in the pipe work to the shower? Have you got them?

Do all the other hot taps work ok?

 

[allan mills]

Hi Dave- all taps and the other mixer shower fine- just looked at installation instructions and it doesnt mention non-return valves.

Do you think a presure reducer on the main cold feed pipe (before the boiler) would help at all?

Good wishes

Allan

 

[gas4you]

Is this a new shower installation, if not has the shower ever worked properly and got hot?

 

[kevindgas]

do a cold test and a hot test on a bath or sink if you get more from cold then a pressure reducer would help but if it is almost equal then i would suspect the shower valve