Danfoss TRV sticking

[Grrrrr]

We have couple of radiators that are cold when all others in the house are hot, only just discovered this as not needed the heating on till now. We have a young baby in the house so need to keep rooms warm for her. It's been suggested to me that it might be the pin is stuck in the TRV and needs a gentle tap to free it. Could this be the case and if so how do I get to the pin? If this works is there any way to prevent the pin from sticking again? It is a Danfoss TRV, not sure of the model so have attached a link to a picture: //www.diynot.com/network/Grrrrr/albums/

Am new to this website and I looked in previous posts but couldn't find one relating to the model on our radiators. Many thanks in advance for any help.

 

[adlplumbing]

take the head off the trv and see what happens

 

[Grrrrr]

that's what I need to know, how to get the head off it to get to the pin. Sorry if I wasn't clear on that. When I looked at other questions regarding this topic there were various answers depending on the model and as I don't know the model I posted a link to a picture of it.
I'm female but am generally good a DIY round the house, so would like to be able to fix this myself as it seems a simple problem and plumbers are expensive to call out. Would rather spend the money on my baby.

 

[adlplumbing]

simple look at the bottom of the head
and you see a silver part made of plastick unscrew it
and plumbers are not expensive
their training is

 

[JohnD]

don't hammer the pin, push it down a bit and let it spring up, push it down a bit further, repeat.

The best method I gave found is to use a large spoon in the palm of the hand, the curvature causes the sping to go straight down. If you accidentally push it sideways, for example trying to use the side of a screwdriver and it slips, it will bend or break off.

 

[nickso]

Not being very clear for the lady are we chaps?


On this model of TRV you grip the lowest part of the black plastic (it has a serrated grip profile) and ,looking from above, turn anti-clockwise while pulling upwards (not into your face though )

Tap the pin gently to release it but be aware they often stick becauae the pin is dirty inside the TRV. It can be cleaned without draining down though.

To replace the head look inside the head at the hole the TRV body goes into, you will see one or maybe two metal tangs. set the head to 5 and hold the head in one hand and rotate the serrated bit again, hopefully both tangs should disappear with a satisfying click. If they do simply push the head back on, if they don't you will have to rotate the serrated bit while pushing the head back onto the valve.

Sometimes it's quite hard to get back on, you may have to turn the serrated bit with a pair of grips if the mechanism is particularly shafted.

 

[adlplumbing]

damn i got my trv mixed their usaly silver

 

[Grrrrr]

Thanks nickso, your instructions were perfect! Tried one last night quickly and got it off (without hitting myself in the face ) and didn't have a problem getting it back on too. Have another 2 to do this morning, just another couple of questions though if you don't mind, how far down is the pin meant to move and also what is the best way to clean it? Many thanks again.

 

[mickyg]

just another couple of questions though if you don't mind, how far down is the pin meant to move and also what is the best way to clean it? Many thanks again.

Just bounce it up and down, by gently pushing down, and eventually it will be moving full travel, off the top of my head i would say its about 5-7mm, but once its bouncing smoothly its generally good. You cant do anything to clean the pin without draining and dismantling, the dirt gets stuck on the water side.

 

[nickso]

just another couple of questions though if you don't mind, how far down is the pin meant to move and also what is the best way to clean it? Many thanks again.

Just bounce it up and down, by gently pushing down, and eventually it will be moving full travel, off the top of my head i would say its about 5-7mm, but once its bouncing smoothly its generally good. You cant do anything to clean the pin without draining and dismantling, the dirt gets stuck on the water side.

Not true.

The pin can safely be removed and cleaned without draining the system.

Make sure the pump is off and simply remove the pin by unscrewing the nut it's held by. A small amount of water will come out but a towel underneath will catch it. Pull the pin out and clean the black carp off it. I put a bit of silicon grease on it and refit....should be good for a few years after that.

Very occasionally the valve will not shut properly and will piis a lot of water out, obviously if it does this stop removing the pin.

 

[mickyg]

occasionally the valve will not shut properly and will piis a lot of water out, obviously if it does this stop removing the pin.

ime occassionally equals most of the time but fair enough

 

[nickso]

occasionally the valve will not shut properly and will piis a lot of water out, obviously if it does this stop removing the pin.

ime occassionally equals most of the time but fair enough

You must be unlucky Micky. 9/10 of them drop no more than a thimble full.

I did one a few years back when the end of the valve seat pinged out to the other side of the room swiftly followed by a couple of litres of pitch black water onto the womans wall and cream carpet. Lucky for me her Vax was more than up to the task and no damage was done. That's one problem in more than 10 years of valve diffin.

 

[Grrrrr]

Thanks for all your help and advice guys, much appreciated. All our radiators are functioning correctly now. May have a go at cleaning the pins though to avoid it happening again. Thanks again.