22mm Isolation Valves Under Combi Boiler - Leaking !!

[InfAddict]

Hi, I have a Worcester Bosch 240 Combi Boiler. Just under the boiler unit (in fact attached to the bottom plate of the boiler) are several isolation valves, the lefthand two being larger 22mm valves.

I drained the system to replace some radiator valves. After doing so, I turned these valves 90 degrees to the off position. I carried out all my work on the radiators no problem.

However, when I've come to turn the isolation valves back to the on position, one of them has started leaking from the swivelling 90 degree bit (i.e. where you place your flathead screwdriver).

I'm guessing the valve is goosed but would like some expert opinions. I've tried everything but can't stop this leaking. Therefore I've had to knock the water off and drain the whole system again. I'm typing this is below zero temperatures without heating or hot water, so advice is much needed!!

What do you call these valves (so I can ask a parts store for a replacement quote)?

Are they just isolating valves or something more special?

Are they part of the boiler or separate (they seem to be attached to boiler by a large hex nut which is clamping the valves onto a metal horizontal plate, which is part of the bottom of the boiler)?

Many thanks in advance. Desperate to fix this asap.

 

[Agile]

You just might be able to stop or reduce the leaking by wiggling them either side of the "on" position.

They can be expensive like £35 each. I would call them "boiler central heating isolation valves".

Of course they may have a different name just to be difficult!

Or they may have the old army classification:-

valves, for the isolation of, boiler parts, Worcester 1994-1998.