thermostatic shower problem

[multitask]

Installed a thermostatic shower which was working ok, but now only runs cold and shower stops when heating knob turned to hot. Could this be a sticking vale or what There is quite a lot of cold pressure and less hot but as iI say it was ok. Any help appreciated.

 

[multitask]

For 'vale' read 'valve' d'oh!

 

[ajs heating]

can be a sticking non return, airlock you don't say if it's mains pressure, gravity,fed from a pump etc.

 

[multitask]

It's gravity fed (in an old pub), cold could be mains pressure or from a header, I've not yet looked.

 

[ajs heating]

check the cold it must be tank fed not mains as it should be balanced pressures.

 

[multitask]

Thanks for your replies.If I find it is direct, can I reduce cold pressure with a valve or a flow regulator, and might this solve things? What I can't understand is that it was working ok and now.............

 

[ajs heating]

cold needs to be straight from tank.
the cold may of over time been putting pressure on the non return and now it's jammed.

 

[multitask]

OK good, if I put a pressure reducer in of some sort will that be ok?Also do I now need to replace the valve? I know these are difficult to answer so I guess the answer will be....try it and see!! Many thanks.

 

[ajs heating]

pressure reducing valve is no good won't balance it needs to be fed from the same tank.
you should be able to free the valve and all be ok

 

[Timmyturtle]

Some showers come with a little flow restrictor that fits at the shower end of the pipe/fitting and reduces the cold flow
Is there any crud/scale in the hot inlet? i have seen this b4

 

[multitask]

should be clean, as it is not that old but will check it out.
Many thanks for your help.