Rad Drain issue

[Livvid]

House 7 rads upstairs 7 downstairs.
Cannot drain downstairs rads for some reason.
All work as per normal, wanted to replace one rad for a larger but cannot simply replace as the rad valve broken, anyway thats besides the point, why can I not get the downstairs to bleed. I have opened all the valves upstairs and induced air as normal, added a drainplug into the lowest part of the system but water from this stops and when you go to bleed valves in any downstairs rad and they still leak water, and so are full still.
I tried bungs in the F&E at first so that I could try the vacuum approach to the rad removal but that didnt work, so removed and allowed to vent naturally, but still no joy in the downstairs rads. Any advice cause and remedy. Cheers

 

[PlumbBobBob]

how are the rads piped? are the pipes coming out of the walls or down the walls?

 

[dontknowitall]

Downstairs radiators are often fed from the landing. So you'll be able to empty one or two when draining the system but you usually have to drain each one individually.

 

[Dotty]

how are the rads piped? are the pipes coming out of the walls or down the walls?

I've been doing commercial systems far too long! That really didn't occur to me!

 

[Livvid]

All the tails are from the floor.The boiler is in the kitchen and on the floor, which was the only drain option, I added a drain valve in the lowest rad feed in the toilet which pipework was in the garage, its definitely the lowest part in the system.
Stumped, rad valve snapped and locked open in the one I wanted to change, but why wont the damn thing drain.

 

[pauls]

is it a concrete floor or a suspended floor you may have to lift some boards to find a drain off. Also have a look around the property at ground level for some sort of access hatch it may contain a drain off, you can find them on bungalows somtimes when pipework is all under floor

 

[Livvid]

Hi yhanks buy Concrete and no hatch at all.

 

[helpsy]

Some places have drain offs situated coming out of the external walls.

 

[Livvid]

Done job today, cracked hallway radiator and bled rest from there, worked a treat. Still a mystery why it wouldnt drain but job now done, phew. Thamks guys for all advice given.