Trying to replace thermostatic radiator valve

[Malcz86]

Hello,

I'm trying to replace a stuck thermostatic radiator valve on a radiator in a combi boiler system. The valve is stuck in the off position and I've closed the other valve.

I've looked at several advice pages online and a few youtube videos. I started by loosening the nut attaching the valve to the rad to drain the radiator expecting a lot of water to come out. But was just a few trickles. So then moved on to the nut on the pipe coming out of the floor. Now some of the advice I'd seen said that there may be a bit of water coming out here so had towels ready, but as I loosened the nut more and more water started spurting out until the several towels I had were soaked, so I stopped and tightened up again.

What did I do wrong?

I switched the central heating and the hot water to the off position before I started, should I have switched the combi off at the wall?

Should I have just kept loosening the nut and eventually the water would have stopped? obviously wasn't keen on trying this incase it didn't!

Or do I need to drain the entire system to change this one valve? I thought I should be able to do it with just draining the rad?

Any help or advise would be appreciated.

 

[IDCHAPPY]

It will usually just be the small pin that's stuck on the valve body,a pair of pilers and some lubricant would have probably done the trick.
To do it the way your doing it you will need drain the heating system first.

 

[Dotty]

Dump the system pressure through the drain off, if you can find it. If you can't you'll have to dump it through a radiator bleed vent which will take a little bit of time.

Close the lockshield valve on the other end of the rad, taking a note of how many turns it takes to close it - this will save you from having to balance the system later.

Wrap a towel or two round the pipework of your trv. Swap the trv body moving a bit sharpish.

Make sure all nuts are tight, open the lockshield the same amount of turns as you closed it, add inhibitor while you've got the system pressure down, top up to about 1bar.

That'll be a tenner please.....

 

[jtsplumbing]

Unless its something you are 100% confident on doing ! call some one in, if you are gong to do it , yes drain the system or you could finish up with very wet floors, and don't forget to replace the inhibitor when you refill system, its the so called simple jobs that cause the most problems,

 

[Malcz86]

Thanks guys, I think I'll have to get someone out. I'm happy working with a spanner but draining the system sounds like a lot of trouble and I wouldn't know where to start with getting the pressure right or adding an inhibitor.

 

[Malcz86]

I did try WD40 but the actual thermostatic valve top won't come off. Have tried loosening the screw below it but it won't turn either. So I think replacing the valve is the only option.

 

[Masood]

Dump the system pressure through the drain off, if you can find it. If you can't you'll have to dump it through a radiator bleed vent which will take a little bit of time.

Close the lockshield valve on the other end of the rad, taking a note of how many turns it takes to close it - this will save you from having to balance the system later.

Wrap a towel or two round the pipework of your trv. Swap the trv body moving a bit sharpish.

Make sure all nuts are tight, open the lockshield the same amount of turns as you closed it, add inhibitor while you've got the system pressure down, top up to about 1bar.

That'll be a tenner please.....

You're cheap!

 

[IDCHAPPY]

You're cheap!

That's what all the sailors tell him.....

 

[Dotty]

You're cheap!

Look at it this way, once I've got his bank details I write a quick promissory to my good friend M'butu Ndonkwe of the nigerian central bank.

He's found tens of thousands of pounds belonging to me, just need to send him 500 for admin fees.

What could possibly go wrong?

 

[Dotty]

I did try WD40 but the actual thermostatic valve top won't come off. Have tried loosening the screw below it but it won't turn either. So I think replacing the valve is the only option.

what valve have you got?

 

[Malcz86]

what valve have you got?

 

[happyflyer]

Dump the system pressure through the drain off, if you can find it. If you can't you'll have to dump it through a radiator bleed vent which will take a little bit of time.

Close the lockshield valve on the other end of the rad, taking a note of how many turns it takes to close it - this will save you from having to balance the system later.

Wrap a towel or two round the pipework of your trv. Swap the trv body moving a bit sharpish.

Make sure all nuts are tight, open the lockshield the same amount of turns as you closed it, add inhibitor while you've got the system pressure down, top up to about 1bar.

That'll be a tenner please.....

Crops,

Be more than a tenner for the new ceiling ...heeeeee :32:

 

[happyflyer]

Look at it this way, once I've got his bank details I write a quick promissory to my good friend M'butu Ndonkwe of the nigerian central bank.

He's found tens of thousands of pounds belonging to me, just need to send him 500 for admin fees.

What could possibly go wrong?

A guy with a violin case knocking on your door and not to wish you a Happy New Year, Mrs Crops dusting the life policy, happy days!!!

 

[Dotty]

That big nut there, that's the locking nut for the head. Use a big pair of grips on it. Make sure the head's turned to maximum open, makes it easier.

 

[Malcz86]

View attachment 20478

That big nut there, that's the locking nut for the head. Use a big pair of grips on it. Make sure the head's turned to maximum open, makes it easier.

Already tried but just end up striping the thread. It's not budging.

 

[Malcz86]

Also by the head you mean the actual plastic bit? that won't turn at all, which is the reason I'm trying to get it off.

 

[Leo21]

I've never not been able to get a head of one of these. Get someone in, this could go badly wrong.

 

[dancinplumba]

Already tried but just end up striping the thread. It's not budging.

Try harder, turns anti clockwise to undo

 

[dancinplumba]

I've never not been able to get a head of one of these. Get someone in, this could go badly wrong.

Wuss 🙂

 

[dancinplumba]

Use a hammer to break plastic head off

 

[jtsplumbing]

I know it's a stupid question but what direction are you trying to turn the large nut ?? As Leo21 changed god knows how meny of these and never had one that wont undo ! :hammer:

 

[kris]

Good pic by croppie as that furled circular nut is what holds the head onto th valve , the pins in that valves are larger than norm ( some are tapered ) and once the heads off you should manage to free the pin,
if you need to remove the whole valve then the heating system will either need fully drained or if the rads upstairs then partially drained,
My advice to a novice would be ( if the system is pressurised and has a pressure gauge ) simply slacken a nut on the radiator side of valve and let radiator empty into tub, once it's totally empty then remove it by loosening the other side nut , once rad is off open one valve and run into basin until it stops, if it's not pressurised make sure the cold water mains off and do as described above, good luck and remember to vent off everything once finished