Trv valve failed

[AndyPRK]

So I have the knob off the end and can see a pin.

A YouTube video came up in my watched list also.

I’m getting about 3mm movement. On the pin. I assume it should be more?

 

[terryplumb]

3 mm is about all they move ,if you press down it should pop up on its own.
Don't pull it up !!
When down its closed ,up is fully open.
If rad still doesn't heat ,turn off all other rads by their trv ( don't touch the valve on their other side). See if the cold rad then heats up.

 

[dilalio]

So I have the knob off the end and can see a pin.

A YouTube video came up in my watched list also.

I’m getting about 3mm movement. On the pin. I assume it should be more?

Turn the TRV head upside down and use the top of it to gently tap the pin and then push on it to see if you can encourage it to free up, it usually works but you have to get a feel for the travel... Its usually about 7-10mm and the spring back is obvious.
If your trv head is brittle plastic, use the side of a pair of pliers or hammer... But gently!

Edit: @terryplumb just made me a liar but, I'm sure most are more than 3mm... maybe it's one of those male measurement things

 

[AndyPRK]

Ok it was stuck in and I’ve freed it.

I’ll give it an hour or so.

 

[Terrywookfit]

Try repeated ****ting of the chrome valve body to loosen the innards.

 

[dilalio]

It leaking and all my other rads not working

If all other rads not working... This TRV won't be causing all that!

 

[AndyPRK]

Try repeated ****ting of the chrome valve body to loosen the innards.

That’s what the YouTube video said to do I’ve given it a bit of a tap. I suspect it is stuck inside.


Typically I added inhibitor in the summer.

 

[terryplumb]

Edit: @terryplumb just made me a liar but, I'm sure most are more than 3mm... maybe it's one of those male measurement things [/QUOTE]
Ha ha ,I did say ABOUT 3 mm ,can't say I have ever actually measured them ,but would be happy to settle for several mm

 

[AndyPRK]

well an update rad still cold.

I've removed the one in the kitchen (which is always on max) and this has a similar movement.

I wonder if I created an air lock in the summer when I drained a bit off to add inhibitor.
I did have to do some bleeding when I first fired the heating up several months ago

The cold one is always on max too, so it shouldn't have failed! as it should always be open and not moving

 

[terryplumb]

If rad still doesn't heat ,turn off all other rads by their trv ( don't touch the valve on their other side). See if the cold rad then heats up.[/QUOTE]

 

[AndyPRK]

Update for your amusement.

After many taps with a hammer over several days, no heat from rad

This rad is in my hall with my stat. It shouldn’t have a trv.
So I purchased a standard valve from Screwfix to fix that and so I didn’t waste money on a trv.

The thread looks wrong.

It appears I need to remove the thread from the rad. Add PTFE and fit new item.

I hope the overall length is correct as the pipe goes straight into the wall.

Maybe I’ll just service it in the summer.

 

[terryplumb]

If rad still doesn't heat ,turn off all other rads by their trv ( don't touch the valve on their other side). See if the cold rad then heats up.

[/QUOTE]
Did you try this Andy ?

 

[AndyPRK]

No good point.

I’ve just put the trv head back on to tidy up for now. I’ve held it in the closed position. I’ll leave it like that for a few hours.

 

[terryplumb]

Take the trv head off ,make sure pin is UP ,and turn every other rads trv off. You will know in ten minutes if the cold rads heating up.

 

[JohnD]

After many taps with a hammer over several days, no heat from rad

I like to use a soupspoon to free the pin off.

Squirt a bit of WD40 into a jamjar, dip a sharp pencil in it, and touch the tip of the pencil to the pin a few times. The tiny amount of lube will run down the pin. If the pin is dirty or corroded, scrub at it with a toothrush until it is bright and clean.

You put the soupsoon in the palm of your hand, rounded part against your skin, and put it on the pin, press firmly down. The shape of the spoon prevents the pin skating sideways and bending, and it spreads the force comfortably on you hand. Try to move it up and down a few times, touch it with the WD40 a few times more. You will then know if it is moving freely up and down.

But as Terry says, turning all the other rads off will give the best chance of getting the flow through your cold rad.