Can Themostatic Mixer Values be faulty?

[skhudy]

Had a shower fitted, guy who fitted it has been sacked (long story) but the shower is just boiling hot. It's like just hot water is flowing through no cold. Shower is mains pressure fed for hot and cold.
Its this one https://alliancegb.com/product/nair...shower-valve-square-head-with-fixed-rail-kit/

There are no instructions, and really nothing to adjust. The only thing I can try is take apart the fitting with the anti scald dial on the right and the central thread / screw inside is turned all the way to the cold, but doesn't make any difference.
The Manufacturers said either the hot water has been plumbed in on the wrong side or there is no cold water running, the valves never fail, they sell thousands.
I've checked both - Can feel the Hot water is on the left hand side as advised, Undid the nut on the right enough to see cold water is coming through

My basic question is, is can the mixer value be faulty, or could there be something else to check?

 

[Lower]

Anything can be faulty. Try adjusting the temperature in both directions just to make sure that you're not accidentally turning it the wrong way.

 

[footprints]

Might sound silly but any chance this is fitted upside down with the connections reversed?
How do you divert between the hand held and rain heads?

 

[skhudy]

thanks for the replies.

It is the correct way up, diverts from hand held to rain head with the dial on the left.

I've just checked the temperature of the water is at 65 degrees (the same as the hot out of the tap so no cold is getting through) - turning the dial doesn't affect the temperature (even taking the fitting off and turning the screw spindle thing with piers)

unless there is something else that springs to mind to anyone I'm going to take the wall fitting off and get it replaced - its TS I don't think they'll quibble. It's just how the manufacturers insisted that the diverter valves don't fail.. Maybe I'll be back here if the replacement does the same?!!

 

[footprints]

Yes no such thing as a mechanical device that cannot go wrong! Or indeed a fail-safe that is truly that
Please update us on the result

 

[terryplumb]

might be stating the obvious but have you checked the filter is not blocked. and non return valve is free to move ? they are both at the back of the mixer close to water inlet.​

 

[rules&rulers]

Return it for a refund.

Get a tried and tested brand like Bristan,(there are others available).

This one works well,fitted many. http://www.bristan.com/products/mixer-showers?code=pm2 sqshxdiv c
The quoted price varies !
It comes with instructions as well,so cant go wrong.

 

[skhudy]

It been too long to have the original returned. Had the mixer bar replaced with a like for like and... it works just fine now. There was a filter washer fitted on the Hot, and the other filter washer on the rain head outlet (not on the cold inlet) Makes me thinks the fitter made the mistake and maybe some crud in the pipe went into the mixer valve?

 

[Doggit]

As you replaced it on a like for like basis, rather than an original replacement, you don't actually know where the fault is, but I had a similar problem recently, and it turned out to be the red and blue stickers were on the wrong way round. When I replumbed the feeds, it worked perfectly.