Danfoss drain off lockshield

[Bushman]

So I'm trying to drain down the central heating system to change a valve out. Problem is the drain off valve is seized. Tried using a bleed key/radiator key but it isn't moving, now I don't want to round it.

The valve I'm talking about is the one below. Now I know my options are to isolate the radiator, crack open the nut and drain that individual radiator and change the drain off with a spare, then drain the system. But is there any tool I'm missing that would make this job easier.

Thanks in advance.

 

[ShaunCorbs]

TBH they do seize in place very often (normally like to crack them / start to turn them when the system is warm)

The best option if that doesn't work is like you said crack a nut and put a container to catch the water slow but always works

 

[Bushman]

Thanks I didn't think about trying it while it's warm.