DIY Doctor UK DIY Forums

Hey,i purchased a mixer shower for my bathroom a year ago and have never been able to get the shower to a decent temperature.I had a new combi boiler installed as the old one was packing in and thought this may have been the problem but it is still the same.The shower is luke warm at best.There is a way to adjust the temperature at the mixer using an allen key although this seems to do very little in increasing the temperature.I found the instructions last night and it says something about fitting a pressure reducing valve? If this is the case where would this valve be fitted,as the mains enters the house? Thanks.

The reason to use a pressure reducing valve in a shower is to correct an imbalance in the pressure of the cold and hot water flows. Typicaly this would be used when you have mains cold and gravity hot flow.

With a Combi boiler both the hot and cold are fed under mains pressure, so fitting one of these in your cold feed to the boiler will reduce both the hot and cold pressure, and achieve nothing.

Combi boilers often have non-adjustable preset hot water temperatures, and produce a fairly meagre flow of hot water, so you are limited as to what you can do.

The hot water from the bolier will cool down as it passes through your pipework. So the further away the more cooling that is likely to take place. If this pipework goes under floor or through any cold areas try insulating the pipes. Also ensure that the two pipes are not touching.

Try restricting the cold water flow with a ball issolating valve. I have tried this, but it only made a little difference.

Good luck.

Okay thanks or your help.I have a plumber looking into it just now for me.My combi isnt far from the shower maybe about 3 metres so hopefully something can be done.The hot water at my kitchen and bathroom sinks is extremely hot so the plumber was thinking the problem could be the mixer setting itself.