Need to avert an ongoing diy disaster. I need to drain my sealed ch system (combi boiler) as I have removed a rad in preparation for new flooring, and the valve is a bit leaky from where the micro bore pipe meets the valve. I want dry floorboards before I fit the new floor. However, I can’t find any drain valves anywhere on the visible pipe work? Any ideas? Can I drain down from the boiler? Any other solution to stop the leak?

Cheers

You can de pressurise the system by opening the valve on the radiator valve you haven’t got the leak. When its dropped, you should be able to unscrew the faulty valve. Make sure you close the first valve you drained. Should hold any water in under a vacuum. That’s what I did recently with an open system when changing valves and thermo valves, by plugging the F&E tank.

Turn off all other rads.
Open the faulty valve with 2 washing up bowls/trays to hand, drain off. It may stop quite quickly, or, it may drain all of the water in the pipes.
Either way, once the main pressure is gone, you may get away with whipping off the old valve and putting on the new with the water still ‘live’.
Or, get a helper handy to pour away the water when one of the bowls is full.

Or, put a hosepipe on the downstairs drain valve, and empty that way.
Draining from the boiler will not help much as the drain off point is likely to be above the level of any downstairs radiators.
If upstairs, then you wont have to drain much water off to do it.

Probably too late but can you not just attach a hose to the rad valve and drain down fully?