water problem

[argylllad]

evening chaps.

got a problem with the job I`m at .

new build house with a private (hill) water supply .good pressure.
water comes into the house and then straight through a filtersystem under the sink.

problem is that when the owner runs the kitchen tap ,or any tap ,and someone flushes the loo ,the flow at the kitchen tap virtually stops.

I`m the joiner. and I`m stumped.

any ideas chaps.
Thanks

 

[MarkAqua]

What pressure is there at an outlet nearest to where the mains enters the house? What size pipework is the CWM in the house and what size is the supply outside coming to the house?

Mark

 

[argylllad]

water is in 22mm copper in the house.

pretty sure the supply coming into the house is in 25mm alkathene.certain its not 32mm

 

[GQuigley67]

crap flow rate probably

 

[MarkAqua]

I'd get who ever installed the filter system and plumbed the house to come back and check over it. Certainly does not sound right. There should be more than enough flow with a 22mm supply throughout. Try a pressure gauge on a tap somewhere in the house and use a flow cup to check what flow your getting.

 

[AWheating]

not the soultion really but you could reduce the flow to the toilet at its isolation valve as a temp fix.