Hi
We have a screwdriver-operated, quarter-turn isolation valve for the outside tap. It was turned off until I fitted the tap on the external screw fitting, so it worked two tears ago. Last year, I turned it off until the Spring and all was OK. This year, I turn it a quarter turn and there is no effect. Is it possible for an isolation valve to fail in this way? If so, is there any solution apart from tedious replacement?
Ta
David