Sticky TRV capping - bayonet fixings retracted locked

[DiyNov1ce]

EDIT: Once off - if the bayonet fixing retracts and locks in the retracted position within the TRV capping housing - how do I get the two fixings to return back out again? As it is, the two TRVs I've taken off are locked in the position of being able to come off - so they would just "sit" on the pipework/valve pin and you could just lift the TRV capping off without twisting anything. So whgat do I do now?



Cold radiator working again, only problem now is getting the TRV backn on without it locking like it did last time when it locked once put back on and I had to use a screwdriver to prize it off.

Its a Danfoss with bayonet fixing and the base knurled ring twists while holding the fixed plain ring just above it. Now I've got it off the two rings have locked and so has the bayonet fixings which are locked in the retracted position. I assume there's a simple way to ensure I put it back on correctly.

 

[buck51]

A picture speaks a thousand words, What type of fixing is it??? from memory some have a knurled chrome screw on fitting, some a clamping ring with a screw and nut, some a grub screw about 2mm allen key required, and I think some are a bayonet fitting???

 

[DiyNov1ce]

A picture speaks a thousand words, What type of fixing is it??? from memory some have a knurled chrome screw on fitting, some a clamping ring with a screw and nut, some a grub screw about 2mm allen key required, and I think some are a bayonet fitting???

It looks very plain on the outside, creamy white shell which is kind of curved/triangular.

 

[buck51]

Now describe what is below the gap, and DO NOT lever with a screwdriver
as that is probably how you broke the other one

 

[Beerlover]

If I'm guessing right you need to hold the cream coloured top and twist the grey part to release the head, cannot remember which way - try both

 

[DiyNov1ce]

Thanks for your time and help Buck51....

The screwdriver to lever off was advice from a plumber on a previous one (couploe of years ago) that got stuck/locked when I put it back on so there's obviously something I'm doing wrong when Im put them back on

Mine looks the same as the one pictured on a post here by Dan Robinson....
//www.diynot.com/forums/viewtopic.php?t=167254

Only difference: mine are poisitioned vertically rather than horizontally.

 

[buck51]

http://www.google.co.uk/products?hl=en&q=danfoss+trv&show=dd&sa=N&start=110
Try this link it may help you to identify which valve you have
And remember Google is your friend, ask Google
If the link don't work just type in danfos trv

 

[buck51]

That looks like a bayonet fitting to me, The back bit nearest the chrome valve is the part which you have to turn about one eighth of a turn whilst holding the rest of the head of the valve with the other hand and it pops off,
Let us know how you get on ,

 

[DiyNov1ce]

If I'm guessing right you need to hold the cream coloured top and twist the grey part to release the head, cannot remember which way - try both

Thanks Beerlover.... on this one it worked by holding the plain black ring and twisting the knurled black ring just below it.

 

[DiyNov1ce]

That looks like a bayonet fitting to me, The back bit nearest the chrome valve is the part which you have to turn about one eighth of a turn whilst holding the rest of the head of the valve with the other hand and it pops off,
Let us know how you get on ,

Many thanks Buck51. I simplified as I had not one but two radiators gone cold. I've now successfully removed both TRV cappings. On both a gentle tap on the pin with a small hammer didn't work so I gently lifted the pin with a pair of pliers. On both it came up easily by about an eighth or quarter of an inch to a kind of notched normal end of travel so the pin was now sitting that bit higher. Both are now working fine, thanks.

Many thanks to both yourself and Beerlover.

Its all coming back to me now.... last time (a few years ago!!) I got to the same stage but did something wrong in fitting the capping back on - and I think it was only then when it was locked that the plumber suggested to use the screwdriver to lever it off!! So, (bearing in mind what happened last time) is there a simple way to make sure I do nothing stupid this time in putting the cappings back on? Do I have to line it up a certain way when I place it back on?

On both the metal bayonet fixings have retracted back into the capping housing and have locked with these metal part retracted rather than protruding so how do I get them back out and the capping back on - do I have to line something up a certain way?

EDIT: at the moment the bayonet fixing is retracted (the two internal metal fixings are retracted within the TRV capping housing) - so the TRV capping would now just "sit" on top of the pipework/valve pin and would be free and able to be lifted off without twisting anything - so what do I do now?

 

[Beerlover]

The pin is stuck in?

To free it get a flat spanner and hold it flat on the top of the valve. Tap the spanner with another spanner, firmly, until it springs out. DON'T hit the pin directly or you may bend it.

 

[buck51]

I have had a chance to look at one of this type today,
As you hold the body of the valve head and the upper of the black rings,(with the valve in the fully open position is easiest)
You turn the bottom ring in an anticlockwise direction, it will then click and lock in the open position,
To refit the TRV HEAD on the valve, Make sure it is in the fully open position, push it on firmly and turn the bottom black ring in a clockwise direction and it will lock back on,

 

[Iolaire]

I have removed one TRV head to try and work out why another won't come off and now the one I removed won't go back on as the lock ring is stuck and tge two wee metal tabs are protruding. Any advice welcome same valve as in photo seen earlier.

 

[Iolaire]

Foolishly removed another to try and suss the proem now I have two in that condition as well as the one I can't remove.