Removed Thermostatic Mixer Valve - Now Hot Water Not Flowing

[SkinnyDogg]

Hello Everyone,

New to the forum and looking for some advice please.

In our bathroom there is a thermostatic mixer valve under the bath. It only has a single pipe in and out which is the cold. After the valve the pipe then joins the hot water inlet for the bathroom. I adjusted the valve to its maximum setting but the water never got hot enough to have a decent bath or shower. Given that it only seemed to be regulating the amount of cold water entering the hot pipe before it hits the taps I decided to remove it. Because of positioning it wasn't possible to cut it out so I removed a section of pipe between the valve and the hot water pipe. I capped off the pipe either end assuming the water would then be ok........

Unfortunately, now when I turn on a hot water tap it is just a trickle. If it is left for half an hour it starts to flow cold at normal speed and then drops to a trickle as soon as it gets hot? The boiler is a vaillant 837 combi and downstairs still works fine. Any suggestions greatly appreciated?

Thanks

 

[snowhead]

Did the Hot water ever work correctly at the Bath?

It seems what you've cut out is a Pressure Reducing / Regulating valve not a Mixing valve.

Anything like these ?: https://www.bes.co.uk/products/110....lebase&gclid=CKrorc3N2MkCFcSVGwodNXoH6g#18862

Pictures would help.

 

[SkinnyDogg]

Hmmmm..... It does look like this may be what I have done. What I don't get is why this would be feeding cold water into the hot water? If I have just removed the supply from this to the hot water pipe does that mean the hot water has only ever flowed at a trickle and has been topped up with cold water to get e decent flow?

Thanks

 

[Masood]

Hmmmm..... It does look like this may be what I have done. What I don't get is why this would be feeding cold water into the hot water? If I have just removed the supply from this to the hot water pipe does that mean the hot water has only ever flowed at a trickle and has been topped up with cold water to get e decent flow?

Thanks

It might have been a relic from an old system where the cold was converted to mains and the pressure reducing valve installed so as not to overwhelm gravity-fed hot.

 

[snowhead]

Yes Pressure regulator / reducer

That chrome piece behind the PRV looks like a mixing valve or is it just a Chrome Tee, is that where the Cold went?

The setup originally would have been Mains cold to the bath (and sink and W.C)
Tank fed Hot to the Bath and sink.

At some point someone has fitted a shower mixer and found the Cold pressure too high so fitted the Pressure reducer.

Another photo of the chrome Tee or whatever it is would help.