Our central heating system doesn't appear to have any drain points in it apart from possibly on the boiler (which is about 6' off the floor). We've a suspended ground floor with pipework running under the floorboards. Without actually taking up all the floorboards around the 3 downstairs radiators to check that someone installed one - I'm a little stuck.
So - assuming for now that there aren't any under the floorboards - what should I do to drain the whole system?
I'm planning on adding TRVs sometime, so I'll just fit lockshields with draincocks on when I do that. However I've found a leak on a solder joint going to a radiator in a room we're decorating. It's been there since we moved in, but we're going to put down a new carpet - and don't want to that if I'm going to need to take it up again to lift the boards to repair the pipe, let alone if its going to stain the carpet before I do that! Depending on how I feel - I may well do all the jobs at the same time - however I just need to get the water out the pipes first!
I know that trying to solder a joint which has any water in it may well fail - however what about compression joints? Do these need to be completely dry before making the joint?
Thanks
D