Low pressure hot water query

bennyl10

Hey all

new build, AW Heat Pump for hot water, just moved in and noticing really low pressure on the hot water, particularly upstairs (cylinder is downstairs)

(unable to really have a shower)

any tips or possible causes before we go to a plumber?

John.G

Is the cold water supply to the cylinder from the mains (unvented cylinder) or is there a pump that takes water from the cold water storage tank (CWST) in the attic and pumps it through the cylinder (also unvented cylinder).

bennyl10

https://www.boards.ie/discussion/comment/119006263#Comment_119006263

as far as I know it’s direct from the mains.

there is a cold water tank in the attic though.

either option a rougher fix?

John.G

It's not supposed to be fed directly from the mains (in Ireland) but some are, have a look at the cold supply into the HW cylinder and it may look something like the attached, post a few photos if possible.

bennyl10

https://www.boards.ie/discussion/comment/119006351#Comment_119006351

This is what we have…

any assistance very appreciated

hot water pressure in showers

upstairs is virtually nothing

John.G

It certainly looks like a unvented system but wonder then why (if) a cold water storage tank is required, can you get a look at this and give rough dimensions and see if there is a vent pipe bent over and into this tank and near the water level.

Also close up photo or details on the white expansion vessel label in your second photo.

You will (must) have a cold kitchen tap supplied from the mains. Is the pressure/flow rate from a hot kitchen tap similar to this?. when you get a chance run these separately into a jug/bucket for say exactly 30 secs to get the flow rates from each.

If a new build in a estate do your neighbours have the same problem?.

If there is any literature laying about re your system post the main details off it.