Toilet Bottom Fill Entry Valve Slow or Sticking

[WSB]

Hi Folks,
A short while back I renewed the bottom fill entry valve in my toilet with a similar Flomaster model.
Sometimes it takes ages to refill, sometimes it's fine.
Are these things prone to sticking and is there some way to resolving the issue?
I opened up the cistern and fiiddled with the valve mechanism a bit and it was ok for the next 5 flushes. Filled up reasonably quickly. But I know it will happen again where it'll go slow or stick again.
Any ideas what the problem could be and how to fix it?
Many thanks.

 

[Newboy]

is the float moving freely on the shaft?

 

[WSB]

Yes it does. Water is from the loft tank too, so pressure should be consistent.

 

[dilalio]

Things to check:
Sediment from tank getting into pipework and blocking filters and/or outlet of flush valve.
Blockage in feed to cistern.
Remove pressure/flow reducer from body of inlet valve.

 

[WSB]

Many thanks dilalio, I'll try that.