Crosswater brand new shower not hot enough

[Jones82]

I have a customer with a crosswater wlbp1501r+ concealed mixer, it is literally months old.

Right from the start they have had "not as hot as they would like" showers, I've calibrated the shower to be as hot as it can possibly be, we still couldn't get the temperature above the 40 degree mark.

I increased the hot water temperature at the boiler and this worked for awhile but now the incoming mains temperature as dropped, due to the winter months, the shower has become tepid again.

The customer has spoken to the manufacture, first they said to fit a pressure reducing valve and this should have been done according to the MI. However I've found the manual online and it only mentions fitting a prv where the incoming main exceeds 5 bar, this is not the case. Round here your lucky to get 3!

We spoke to the manufacture again and this time they said the difference between the hot and cold must be 0.5 bar at most and the prv should be calibrated to achieve this... I have never had to do this on a thermostatic mixer shower and this is not mentioned in the MI.

Lastly, the customer has a brand new fitted kitchen, fitting a Prv would be a bit of a ball ache, could we turn the stopcock down to achieve a similar result. I realise it won't change static pressure (classic flow and pressure difference) but it could lower dynamic pressure? Also the hot and cold are fend from independent supplies, so limiting the cold stopcock will not affect the hot supply.

Thanks for your help

 

[ShaunCorbs]

I would say boiler fault if getting more than 0.5 bar drop between cold and hot pressures and make sure who ever you get is gas safe reg

Are the shower filters clean ? And non return valves not stuck shut ?

 

[Jones82]

Yep filters etc clear I was also leaning towards the boiler, heat exchanger or just low heat output
Oftec, its an oil boiler

There is a marked difference between the hot and cold through out the house, the boiler seems to be restricting the hot to obtain the required temperature.

I've had mira and aqua lisa showers cope better with this though, the crosswater mixer seems less forgiving to the difference

 

[REDSAW]

unbalanced supply?

 

[Jones82]

Interesting, I don't think so. The stopcock servicing the hot water supply is relatively new. It could be checked using a pressure gauge inline before the boiler?

 

[REDSAW]

i find the answer in your first post from the m.i or..
the supplies are the wrong way around or debris in filter!
either way have you tried running the hot into a bucket direct?
this will give the answer to supply fault.

 

[Jones82]

No and no I'm afraid, supplies are definitely right way round and filters have been checked

 

[REDSAW]

is there an internally adjustable anti-scald thermostat & what open flow temp does it give ie no shower attached?