Radiator Leak, shut off water?

Cpmeckley

I have a leak in an old radiator and am trying to get the leak to stop, but can't figure out if I can isolate and drain this single radiator. I have turned the valve on the left to closed, but nothing seems to change significantly. Is my valve broken or am I missing something? 

bburd

What part of the radiator is leaking? Is it the radiator itself, the supply valve, or something else?

That looks like a hot water system, not steam. Turning off the valve will reduce or stop flow through the radiator, but will not remove the water pressure. It will simply come up through the return pipe.

You would have to turn off the boiler, turn off the makeup water supply, and drain the heating system down below the level of that radiator to empty it. Also open the air bleeders (which should be at the top of the radiator above the return pipe) on all radiators at or above that level to allow air back in.

Unfortunately, you cannot run the heating system that way, so you would have to repair the leak, refill the system, bleed the air from all radiators and restart it promptly.