Stone cold radiator - closed system

[robbobob]

Hi,

I've got a cold radiator attached to my combi/sealed heating system. I've checked the pin underneath the valve and it moves freely. I also closed both sides of the radiator (valve and square tap) and removed the radiator.

When I have done this before on other radiators, it hasn't affected the pressure of the system as a whole, but this time, it put the pressure down to zero and the boiler did an error-reset. Should it do this, as I thought closing both sides of the radiator should retain the integrity of the system?

I put the radiator back on, bled and refilled until the pressure got back up, but i've still a cold radiator.

I wasn't in the house when the radiators were fit and the floor in that room is tiled over concrete, so i can't easily have a look at the piping. Does this sound like an obvious fault? Any ideas?

 

[Balenza]

robobob wrote

I've checked the pin underneath the valve and it moves freely

The pin is separate from the internal plunger which still may be seized and impeding the flow through the rad.

 

[gigz]

Take the rad back off and open both valves into a bucket to see if theres flow to both, while rads off check that its not blocked.

 

[robbobob]

I'll have a bash at it again tomorrow. I think that since i took it off this morning, it's actually working very, very slightly. It seems a couple of degrees off absolute zero (where it is normally at).

Thanks for the replies.

 

[ChrisR]

COuld be an air lock - turn off most other rads so more flow has to go through it.

 

[robbobob]

I was about to remove the rad again today and lo and behold - it was working.

Thanks for the help guys.