Hi all
Got a bit of a headscratcher in my new build.. Had the site plumber out a few times to this but no further forward so as a last resort I thought I'd ask on here to see if anyone has any ideas.
The issue revolves around the water pressure (flow rate?) to the upstairs hot taps, specifically the bath hot tap. We have a cold water tank in the loft, a smaller header tank next to it and a hot water cylinder in the bathroom cupboard - the cold and hot water are pumped via a grundfos pump to the taps throughout the house. To my knowledge, only the kitchen cold tap and maybe the cisterns are mains fed. The pump was replaced a while back as it was incredibly noisy, we now have a much quieter version.
The hot water pressure in the bath tap is extremely low, taking maybe 1/h hour to fill a bath, this is even with it being pumped by the grundfos pump - the cold tap is fine, coming out at a fair old rate. The thing is, the hot water used to be exactly like the cold water until the pump was replaced, but now its unusable. Its the same pump unit, but just hot and cold pipes on either side - so I know the pump is more than up to the task if you look at the cold water.
Also, I thought it might be an airlock so I ran the hot taps for a bit - maybe 10 mins - we ran a bath too and noticed that the hot water tank was still full.
So the question is - what's going on? Can it be that the hot water is coming straight from the boiler - ie bypassing the cylinder? Hence the low rate?
Many thanks for reading
Martin