Drain-off on rad only releasing drip.

[Draughtsman]

Replacing the rad so I'd like to drain this down 1st, but having fully undone the sq release nut on the drain-off spiggot it just drips. If I open the air bleed valve on the top I get water out of the air bleed, but still virtually none out of the bottom drain-off spiggot..

Thank you.

Dain

 

[Mottie]

Probably blocked with sediment. Try tapping it a bit.

 

[Draughtsman]

The flow does increase with tapping and opening/closing the drain-off.

I could crack a lockshield or trv connector nut or maybe completely unscrew the drain-off, but I think the lockshield or trv aren't closing off supply as the air bleed is still releasing water instead of drawing air in.

 

[terryplumb]

Is the system pressurised / sealed ,or fed from an f&e cistern ?

 

[Draughtsman]

Pressurised Glow Worm. The amount of water released dropped the Bar down to zero so I restored the pressure to come away from it and have a think.

There's laminated click wood down so I'd like to avoid a deluge.

 

[terryplumb]

If you close both that rads valves and the drain cock,then open the air bleed valve, water should come out of the air bleed for a little while and then stop. If it doesn't one of the rad valves isnt fully closing ,and you will need to manually drain the radiator,after draining the system from some other drain cock.