Stuck radiator valve

[paulm]

Any tips for freeing up what seems to be a stuck thermostatic radiator valve ?

It's a Drayton type, the whole radiator is stone cold, doesn't need bleeding, so assume the valve is stuck in the closed position as the inflow pipe is hot but the rad and outflow pipe cold.

Unscrewed the top of the valve and took it off, and the brass pin in the valve was depressed, pulled it up with a pair of pliers but don't think that has actually done anything to the valve itself. Worth some sharp taps on the side of the valve with a hammer, application of a blowtorch or anything similar, or do I just need to replace it ?

If replacement is best, any tips on doing so without having to drain down the system ?

Any help appreciated !

Cheers, Paul

 

[9fingers]

Hammer should do it. If you need to replace it then either drain down or use a freezing kit. Not sure how a pressurised system behaves with a freezing kit? maybe you have to work quicker.
Whilst you have it de-commissioned fit service valves for next time.

good luck

Bob

 

[Doug B]

Hi Paul.

With the heating on, tap around the underside body of the valve with a hammer.
Support the valve with your hand as you tap it, you`ll know when the washer lifts as the heat will come through.

HTH.


Cheers.

Edit Bob types quicker than me

 

[paulm]

Thanks guys, will try the tapometer approach in the morning and see how it goes !

Cheers, Paul

 

[sparkymarky]

try whacking it with a hammer, if that doesn`t work then replacement will be the only option.

is the system a open vented or a sealed system, if sealed then release the pressure on the drain point, then turn off the drain point, then shut the lockshield radiator valve on the other side of the rad you should then be able to whip one trv off and replace with another as there are no open ends. if open vented same principle but you will need to bung the vent and feed on the tank in the loft.

hope this helps.


blimey everyone writes quickly here

 

[henton49er]

Paul,

I usually do what you have done (lift the pin with pliers). I then push the pin back down using the side of the pliers and with a gentle tap from a small hammer if needed. I repeat this a dozen or so times trying to free up the pin. It has always worked for me in the past - hope it can work for you.

Mike

 

[paulm]

Thanks guys, the hammer did the job !

Now nice and hot and no need for anything more complicated thankfully.

I do remember that I got a couple of rubber bungs a few years ago for popping in the header tank pipes to stop the system draining (it's a normal vented system), but never had to use them yet thankfully as I suspect there would still be plenty of opportunity for mess and ruined carpets, and access to the header tank requires you to be a midget with four foot long arms to get to it in the tiny loft space !

Cheers, Paul

 

[RogerS]

Resurrecting this thread, if you have the situation where the pin does pop back up and clearly is able to work up and down against the spring....but water still does not flow when the pin is in the fully up position...does this mean that there is some gizmo inside that is all clagged up?

And if so is there a fix?

 

[CHJ]

Probably means there is some gunk blocking the underside of the small hole that the controlling pin works in a few sharp taps down on the pin with a small pin hammer often shifts it out of the way, forces a drop of water in reverse flow direction. (dependant on flow valve type of course)

 

[RogerS]

Tried that, Chas.

 

[MMUK]

Resurrecting this thread, if you have the situation where the pin does pop back up and clearly is able to work up and down against the spring....but water still does not flow when the pin is in the fully up position...does this mean that there is some gizmo inside that is all clagged up?

And if so is there a fix?

If that happens it usually means you need to flush your system as it's become clogged with calcium deposits. TBH, for the cost of a new valve it's not worth the hassle o0f stripping down.

 

[RogerS]

Mmmm...I agree. That was the conclusion I was coming to. A job for Summer! Just hope I can find a replacement valve with the same dimensions re pipes. I have NO leeway.

 

[RossJarvis]

Just be careful, Christmas eve a few years ago I tried the Birmingham Screwdriver, tapometer trick on mine. Shortly there-after I was at B&Q purchasing a number of items including copper elbows, pipe, radiator valves, blowtorch etc. I only had to drain the system 4 times before it stopped leaking

Still, it was a heck of a lot cheaper than calling out a plumber

 

[MMUK]

Still, it was a heck of a lot cheaper than calling out a plumber

I'll bet it wasn't after her indoors finished making you pay for it :lol:

 

[RogerS]

The good news is that I found a spare Honeywell TRV...not the correct orientation as a direct replacement...but it did let me investigate how these things strip down. Looks as if I should (after draining down the system) simply unscrew the plunger assembly from the valve in situ and that will then let me see what is going on. The actual stop-washer is fixed to the plunger that goes up and down and so for it to have blocked the valve it must have (a) come off the end of the plunger and (b) somehow 'glued' itself to the valve seat.

 

[dericlen]

Hi RogerS,
Your problem trying to repair an old valve could end up being expensive in the long run. After toooo many years in the building trade I have seen it before, especially, should you choose to "flush" the system using strong chemicals that will find the weak parts of the system and cause a leak. A simple valve replacement, removing the rad and rinsing it through with tap water at the same time, could be your best option.
Good luck.
dericlen

 

[RogerS]

Hi dericlen....many thanks for your thoughts. The system has already been power flushed not that long ago and the rad has already been off and cleaned out as part of the bathroom refurb. I'm just proposing to drain down as much as is necessary to empty the rad and any pipes that will feed it, undo the insert and have a looksie. Then top-up with inhibitor and away we go....hopefully!