Replacing a lock shield valve

[thebanishedone]

Hi All,

I want to replace a lock shield valve in my central heating system. It’s a combo boiler system. If possible, I’d like to do it without draining the whole system.

Is there a way to just drop the pressure so I can whip the old valve off and replace it without letting too much water out of the system?

Cheers.

 

[CBW]

Yes it can be done. Probably best closing both valves on the one you’re replacing, then relieve the pressure via the bleed vent until water stops flowing. Disconnect the nut to the radiator and blank with a compression stop end of the same size, then release the pressure from the valve into a suitable receptacle by opening. Then when water has ceased to flow, undo the valve nut and replace, fill system open other valve and bleed rads.