Hi, have a Worcester 35CDi II combi, and everything was fine until plumbed up shower mixer valve. Now, whilst the heating works fine, the hot water only cycles between lukewarm and cold (with the boiler switching the heating off soon after it goes on).
Now there was some vague blurb in the mixer tap fitting instructions about the water pressures. We have very high water pressure here ~5Bar, and I a quick Google has brought up a single mention of someone seeing something similar, that the pressure of the cold water is going through the valve and back down the hot output.
Can someone elaborate on this? What are my options on how to fix this? Fit a pressure reducer to the cold feed? What sort of pressure will my combi hot side have? I always thought it was the same as the mains pressure when you had a combi....
Mixer PDF:
Maximum Water Pressure Concealed Dual and Triple Control shower valves are suitable for use with all water supply systems up to a maximum of 5.0 Bar. Operating pressures above 5.0 Bar will require the installation of pressure reducing valves."