Ball valve problem

[Keeto]

I changed my ball valve a few years ago only to have the same problem (overflowing) start up again a few months later.

Do the learned panel think replacing the valve with a plastic type will help as the other two valves are brass

 

[Bahco]

Do the learned panel think replacing the valve with a plastic type will help as the other two valves are brass

Not really. Which tank s overflowing and what is the water level when cold

 

[JohnD]

as Bahco has in mind, there is probably some other cause

however it is worth having a look at the valves in case you are suffering from a lot of grit or sediment or rusty pipes or something interfering with the valve action, and to make sure they are correctly fitted and tightened.

If you are able to (a service valve is handy) it is useful to turn on the supply pipe briefly while you have the valve off, to see if it washes rust or anything out of the pipe. But if you have rusty pipes you will probably see grit at the bottom of the tank.

 

[Timmyturtle]

I have had a few problems ,over the last couple of years,with poor quality ball valves (supplied by different reputable companies)
They are brass construction
The fault i find is the white plunger ,that the brass arm operates against, sticks against the hole it slides in at a funny angle.
This seems to be the plunger is poor quality and not strong enough (water pressures here are 4 bar)
I now fit BETA (make)valves as i have always found them to work,although not so easily obtainalbe locally