Cistern Not Always Filling Up With Water

[SLAN]

Greetings all

I have a cistern upstairs which does not always fill up with water after a flush. It's a Kohler one but not one with a handle, but a knob on top that you pull to flush (not sure if this has any effect - just giving as much info). I also note that the water pressure upstairs from the sink faucets is rather weak.

Pic of cistern attached.

Any tips on how to remedy would be most appreciated.

 

[arctic bill]

do all water devices have low water pressure?

 

[Geofd]

Like arctic bill asked, is the pressure low everywhere , upstairs, in hot and cold, is there a shower also have you checked the aerator on the faucet???? Can you show the fill valve, under the tank cover????

 

[SLAN]

Thanks for the responses. I took short videos of water flows for the 2 sinks upstairs as well as the bath and shower they share with. I also took videos of the sinks downstairs showing significantly higher pressure.

 

[SLAN]

Like arctic bill asked, is the pressure low everywhere , upstairs, in hot and cold, is there a shower also have you checked the aerator on the faucet???? Can you show the fill valve, under the tank cover????

Thanks

Here's some pics.

 

[JG plumbing]

Looks to me like your need a new fill valve since it seems to be flowing into the over flow tube fine.