Hi recently tried to drain all radiators, but 1 of the drain valves needs replacing as it is corrode, blocked and in an akward position, i did not have a spare valve at the time, its downstairs on a loop, is there a quick and easy way to replace it without draining the whole system again!
Freeze (using pipe freezing kit) the pipe on which the valve you want to replace. Follow the instructions VERY carefully. It's easy to rush it thinking it's frozen and find out (too late) that it isn't.
Change the valve on the pipe.
Reconnect valve to rad.
Wait for ice plug to melt (iro another 15-20 mins).
Alternatively if your feeling VERY brave you could do it with the pipe live after draining the rad - ie without freezing. You WILL spill some water - just how much depends on how confident and quick you are. Not really to be recommended though if you've not done it before.
thks for that roseberry, food for thought . Problem with this drain valve is that its about a foot away from the rad valves i wonder whether to leave it alone and fit one of those valve/drainvalve all in one jobbies?
Rosebery says: "Freeze (using pipe freezing kit) the pipe on which the valve you want to replace. Follow the instructions VERY carefully. It's easy to rush it thinking it's frozen and find out (too late) that it isn't."
its also easy to be overeager and burst the pipe with the ice plug when using freezing kits as i found out once to my cost! there's a bit of a knack involved with those things but they do get you out of a hole.
stick a plug in the expansion pipe and cold feed. Make sure system is all off. Slowly and carefully loosen joint you ar working on and releive pressure, the water will slow right down and you can replace your part. Remove bungs.
Note you will need a really good seal. If the header tank starts filling when you are loosening your joint then you have not got a good enough seal, hope this helps.