Radiator valve seems stuck

[d000hg]

We noticed this radiator wasn’t getting warm. Bled it and removed the TRV. The pin has less than 1mm travel even after applying 3in1 and jiggling it several times over the last week.
The pipe below does get warm now (before it was totally cold) so clearly there is some flow but nothing else does.

But the pin looks quite far out to me. I can’t push it in or pull it out, could there be a different failure/problem? Is it just a case of replacing the valve or can I try something more first?

 

[Harry Bloomfield]

But the pin looks quite far out to me. I can’t push it in or pull it out, could there be a different failure/problem? Is it just a case of replacing the valve or can I try something more first?

Try pressing the pin in/down, with the edge of a tool, against the spring - it should be able to be pushed a couple of mm. If not then the pin is stuck down...

Try to release it, by turning, pulling up, with a pair of pliers.

 

[d000hg]

Tried all that already. It was originally totally immobile, after oiling there’s probably 1mm movement when I use a spanner.
However i thought the pin should push in all the way to close, to my eye it sort of looks open (?) but still very minimal flow.

 

[terryplumb]

Try giving the body of the valve a sharp rap with a spanner on the side of the body.

 

[Bod ...]

Looks to me like a designer radiator.
Has it ever worked ?
If not you may find that the radiator is directional.

Swap the valves with each other. While you drained the system buy two new decent valves.

 

[MisterBoy]

Looks to me like a designer radiator.
Has it ever worked ?
If not you may find that the radiator is directional.

Swap the valves with each other. While you drained the system buy two new decent valves.

yes it's worked for 5 years at least without any problems. It's a tall vertical radiator, we have several of them - nothing fancy. This valve is the IN (checked that already) and based on the thread it is fairly new.

When I grab the pin the pliers and wiggle it side-to-side a tiny bit I can hear the water suddenly coming in so I guess the valve itself has an issue. I've seen stuck pins before but they always look quite manky whereas this appears clean and shiny, it just doesn't work. It worked fine one day then not the next.

 

[Harry Bloomfield]

When I grab the pin the pliers and wiggle it side-to-side a tiny bit I can hear the water suddenly coming in so I guess the valve itself has an issue. I've seen stuck pins before but they always look quite manky whereas this appears clean and shiny, it just doesn't work. It worked fine one day then not the next.

Once freed up, the pin should default to up, under pressure of a spring - which is TRV open. Can you not feel the pressure of the spring, under the pin?

 

[MisterBoy]

Once freed up, the pin should default to up, under pressure of a spring - which is TRV open. Can you not feel the pressure of the spring, under the pin?

I can't push the pin down at all from the position in the photo. I think it may be slightly more open the more I work on it but it won't go back in. I was starting to wonder if there could be something physically blocking it inside - a bit of crud flowing around the system - but had imagined the inner workings are sealed.

I'm going to find another rad with the same valve and test the limits in/out on the pin. I thought the pin was supposed to recede fully into the head when totally shut and mine clearly is not like that.

(also sorry apparently I had a different old login on my PC to my phone and have now commented as both on this thread, if anyone was confused I am the OP)

 

[Harry Bloomfield]

I'm going to find another rad with the same valve and test the limits in/out on the pin. I thought the pin was supposed to recede fully into the head when totally shut and mine clearly is not like that.

The pins never push down/in all of the way.

 

[Bod ...]

Forget about the valve for now.

Do a you tube search on how to balance system with the attention on the tall designer radiator.

With a rubber mullet or the butbof an hammer tap ports on the radiator. This is where the horizontal tubes top and bottom meet the vertical tubes.

I suspect these ports are blocked with black debris iron oxide.

 

[lloyda]

Looks to me like it could be a TRV with a integrated balancing insert, such as a Honeywell Valencia. If that black part in the centre has a hex head, and numbers on it, try undoing it slowly. You should find that the pin travel increases.