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[Solved] Hot water issue, never seen this before: Grant Heat Pump and Cylinder
Hi all. A faulty mixer valve sounds like a likely cause to me too. Failing that there could potentially be some cross-flow going on; I notice on the photo of the combination pressure reducing valve, that the balanced cold outlet is plugged. Maybe there's a point in the system at which the higher-pressure cold supply is overpowering the reduced-pressure hot supply, travelling the wrong way down the hot draw off, and subsequently cooling the top of the cylinder down. A bit of a long shot, but this could be something to explore if a mixer valve issue is ruled out.
hi Tom, thank you and thanks to everyone else who replied.
it turned out to be a faulty shower that was causing the issue. This was closed off by a plumber and it fixed the issue straight away. Has now been replaced.
took 3 different plumbers to figure it out but we got there. Nothing to do with the pump or cylinder in the end.
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