Pressure reducing valve scolding water

[Dave Bray]

Hi everyone,

I am having a problem where:

The shower powered by an oil fired boiler is:
Getting too hot after fitting a pressure reducing valve - fitted as mains water pressure was increased - making shower lukewarm

The pressure reducer is set to 3 bar and servicing a bungalow with two bathrooms with shower and two kitchens. Not much pipe run.

Does not matter how much flow is set on shower... water is scolding and boiler is set at lowest setting about 1 bar (max three)

Any ideas what could be causing this?

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[Exedon]

Bit of clarity required.
Do you have a oil combi boiler?

 

[Dave Bray]

Yes oil combi

 

[flameport]

Is this a thermostatic shower - if not, then get rid of it as it's dangerous.

The fail is most likely grit or dirt got in when the other plumbing work was done and has clogged or damaged the shower valve in some way.

 

[Johntheo5]

Thought oil fired combis heat the water to 80C and have a thermostatic mixing valve to then reduce it 60C or so on leaving the boiler but maybe this one is working OK.

 

[Dave Bray]

Is this a thermostatic shower - if not, then get rid of it as it's dangerous.

The fail is most likely grit or dirt got in when the other plumbing work was done and has clogged or damaged the shower valve in some way.

Yes thermostatic and had a new cartridge recently...

 

[flameport]

Yes thermostatic and had a new cartridge recently...

Take it off the wall, take the cartridge out and clean it.
Also flush out the pipes before reinstalling the shower.

 

[Dave Bray]

Take it off the wall, take the cartridge out and clean it.
Also flush out the pipes before reinstalling the shower.

Thanks will try that...

 

[Exedon]

Thought oil fired combis heat the water to 80C and have a thermostatic mixing valve to then reduce it 60C or so on leaving the boiler but maybe this one is working OK.

Yes they use a blender valve factory sealed and shouldn't really be tampered with.
As above I'd be looking at shower mixer cartridge and any inlet filters on shower valve first.