I am trying to fit a motorised replacement valve to my heating system. I have turnrd off thr water supply either side of the pump, but when undoing the joints on valve still get lots of water out. Could anyone advise if tou have to drain complete system to carry out this task. thans
I tried this but the water still leaked as the old valves would not close up fully. I ended up draining the tank. This was easier than expected. I found it easier to replace the valves each end of the motorised unit at the same time which will give longer life to your system free from leaks.