Someone removed the handle, probably many years ago, for a reason - today the problem is much worse. Turning handle = 0, Moving Wall = 1. First time it would have come in handy (the opposite end of the rad is now leaking! Which, is the best plumbing "bad news" I've had in a while - problem with underpowered pump resolved. After many days of religiously bleeding this noisy rad, I got water! Ya, finally. A short time later... What is that dripping noise? DOH. How can I turn off the water? DOH x2.