Toilet inlet pressure problem

[av monkey]

Hello guys, could someone give me a bit of advice. Recently found en suite toilet over filling over float over flowing down toilet pan after several hours.
Its filled reasonably quickly and appeared to shut off.
Anyway. Called plumber because wanted it sorted quickly and efficiently.
The house is 10yr old. Has a confeletti pre-set prv under sink. I could not see a isolation valve under toilet and so shut of stopcock. Later realised there is one tucked under cistern.
He turned off isolation valve and turned back on stopcock. After taking of float arm assembly (Torbeck) hoping to replace with the new torbeck assembly found water pressure was now low. 3-4 mins hardly half full.
All he's done is remove float arm assembly leaving body in cistern and operated stopcock and isolation valve. He thinks there may have been some grit stopping shut off torbeck assembly which is now dropped to isolation valve. But will have to remove toilet to get to get to valve and pipes as its not straight up into cistern but in the boxing behind/below pan. We can't understand how it could have change otherwise.

 

[Best]

Torbeck valves used to have a filter built in where the washer pushed against - in the top of the main body. It blocks very easy.
The newer Torbecks have the filter in the stem & if it is a height adjustable type then i think it can be accessed from taking stem apart perhaps. (been a while since I looked at any) Less likely would be a bit of dirt in the isolating valve.
Maybe the plumber doesn't know much about Torbecks.
If possible, get a Fluidmaster Pro valve (brass tailed version) - they are far better as the Torbecks are not what they used to be!

 

[av monkey]

Hi there. the original stem is still in the cistern which is why we are confused why it would seem to have dropped in pressure with the top off . the new torbeck has a different stem. he said the new one u can just change the top half.

 

[Aquazone]

Could try taking the top off the Torbeck and turning water on (slowly) to see if it will flush any debris out.

Otherwise, as Best has said, replace with a Fluidmaster.