Lockshield valve spindle won't turn

[honestworker]

Hi
I closed a lockshield valve (and disconnected it) so that I could replace a radiator. I reconnected the lockshield to the new radiator and then found that the spindle would move only a fraction of a turn and then stop. Even some gentle force will not turn the spindle.
Does anyone know what has happened?
Will I have to drain down the system and replace the lockshield valve?
All replies appreciated. Help!

 

[Madrab]

It's jammed - either the thread on the valve or the jumper with the rubber seal - it may go with a bit more persuasion and then it'll click and unwind, give it a spray with some penetrating fluid first.

 

[Mottie]

Will I have to drain down the system and replace the lockshield valve?

Is it a sealed system?

 

[honestworker]

It's jammed - either the thread on the valve or the jumper with the rubber seal - it may go with a bit more persuasion and then it'll click and unwind, give it a spray with some penetrating fluid first.

Thank you, Madrab, for the quick reply. I did exactly what you advised. I ran penetrating fluid down the spindle overnight. This morning, I used a litlle bit of extra force and the spindle 'jumped free', as if it had forced it's way past a bit of rubber washer. Thank you again.

 

[honestworker]

Is it a sealed system?

Thanks for the reply. It's a combi system. If it had been necessary, I would have taken pressure out of the system by opening the drain cock. I assume that I would have had to drain the whole system to change the lockshield, as the new radiator is in the kitchen.

 

[Madrab]

This morning, I used a litlle bit of extra force and the spindle 'jumped free'

Yeah - when an older compression valves are locked down tight then the threads tend to bind together as they're only softish brass, so sometimes they need a little extra persuasion.