by Kenj »
Tue Mar 29, 2011 2:52 pm
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.