Draining my sealed system

[andyjc]

I have a combi boiler and need to drain the system since a couple of radiator valves are leaking. If I've got this straight, all I need to do is to open a drain valve downstairs, open a bleed valve upstairs and hose the water out the window. Therefore I don't need to shut the water supply off as long as the valve that I use to fill the system when the pressure is a bit low is shut. Is this correct?

Also the valves that are leaking seem a bit old. The inlet and outlet are on the same side of the radiator. The inlet (which of course has the on/off) is the leaking bit. This fits into the outlet and the outlet then fits into the radiator. I've been to B & Q but their inlet valves all seem to fit directly into the radiator so the size of fitting on the inlets to go into my outlet is too big. Please, what can I do?

 

[theome]

Hi ,yes so long as the filling loop is at least turned off or disconneted,you can drain the system.You will hopefully have a bleed piont to attatch a hose in the lowest point in the pipework.You will need to undo the air bleed valves in the top of each rad. to help empty.Work from the highest point down one at a time.Cannot make out the second part at all. Most valves can be fixed with plumbers tape.If leaking from the nuts on either side of the valve a few turns of around the threads and then retightening should work.If water is seeping from the top of the valve,tightening the nut slightly may stop it,or remove the nut and bulk up the gland packing with tape ,then retighten.When you refill add inhibiter,very important.Reading again,if the leak is from the rad. itself you will need to get a rad.spanner undo the tails which fit into the rad.,tape and tighten.Good luck