cold water 28mm gate valve stuck open

[glider26]

Hi,

We bought a house recently and I've just found that the cold water 28mm gate valve is stuck open. It is as far as I can see the only way of cutting off the cold water supply from the tank situated in the loft.

I suspect it hadn't been open for approximately 10 years. Any recommendations on how to get it unstuck? Is it limescale that gets these things stuck? Is there a product I can add to the cold water tank to remove limescale? Blowing a hairdryer on the valve to release it? Tried WD40 already and a bit of knocking with a hammer.

I'd rather not have to replace it but if I do, I guess I'll drain the cold water tank first, remove the old valve using a pipe wrench and replace with a new one with a compression fitting?


Thanks.

 

[PlumbGas]

Always happens, bung the tank and replace only real option, blowtorch may do the job but if you do get it closed when you try to open it it will probably break, so just replace it with either a pegler gate valve or a full bore lever valve.