Water pressure low upstairs

[Marnhullman]

I have a 3 1/2 year old house with a sealed system and pumped hot water. The pump is connected to the central heating timer so only operates when the hot water is being heated. We therefore have pumped hot water first thing in the morning and in the evening.

The incoming mains pressure is okay but the pressure upstairs is not. When either hot or cold taps are opened there's an initial spurt but then the flow slows significantly. My neighbour's water pressure is fine on both floors.

I have cleaned and de-scaled the tap filters and I can't find a pressure valve near the stop cock, which I believe is not a requirement if the incoming pressure is not more than 3 psi?, although I would have expected there to be a valve in an otherwise high spec new build house?

Could the low pressure be caused by the DHW pump not functioning as it should? Bear in mind the pressure doesn't seem to change whether the pump is operating or not. The pump does work because hot water comes out of the tap instantly when its on but there is a flow of cold water initially before the hot water flows when the pump isn't running.

Could there be a blockage in the pump?

Any thoughts appreciated.

 

[HERTS P&D]

Post a picture of any pumps you have.

Andy

 

[Marnhullman]

It's a Glow Worm Energy 18s boiler with the first pump. The DAB pump is in the airing cupboard adjacent to the hot water cylinder.