stuck service / isolating valve

[Notch7]

How do I free? (mixer tap is leaking, needs new washer / disc)

Its a compression fitting on sink hot tap (the inlaws).

Unfortunately its already had its screw slot a bit chewed.

I thought heat might work, then penetrating oil.....

system is in a bungalow, hot water tank same level as boiler, seems to have pump on hot water from boiler to tank coil. Havent looked to see if there is a stopcock on the hot water out of top -is that likely?

Cheers

 

[Newboy]

Havent looked to see if there is a stopcock on the hot water out of top -is that likely?

No - but there might be one on the cold feed into the tank

 

[Notch7]

No - but there might be one on the cold feed into the tank

Will turning the cold in, stop hot tank emptying

 

[Newboy]

Yes, if you stop the cold entering the cylinder then the hot won't be pushed out.

If there's a stop on the cold inlet (usually low down on the side of the cylinder) then use that or check the loft tank for a stopvalve on the cold water feed to the cylinder. All this asumes you have an open vented system.

If it's a mains pressure cylinder then close the incoming cold main.