Can't isolate radiator

[Sanjay Savani]

I have a valve on the feed/return of the radiator and i cant shut it off. The trv end shuts off but all my radiators have this (as shown in pic) on the other side which i cant isolate with to change radiator. Help please do i need to drain the whole system to remove one radiator?

 

[Riley]

Is the part in your hand a cap

 

[Sanjay Savani]

Yes it tightens to the outside thread so that being on makes no difference just looks pretty.

 

[Riley]

Difficult to tell from the angle but is it an Allen key type slot?

 

[Sanjay Savani]

The inside is round so not allen key. And the outer nut thing wont turn on any of the rads.

 

[Riley]

The centre of the nut is round but is there a different shape below that in the cavity

 

[Sanjay Savani]

Not sure. It was a mates house he bought an i took that picture earlier today. I will check and see if it ia allenkey inside. I will get back to you on that one tomorrow. Thanks for the reply. Much appreciated

 

[Riley]

Pleasure

 

[Best]

Either a slotted screw or an Allen screw below the caps. Most likely Allen screw on modern LS valves that have no exterior spindle

 

[king of pipes]

As above needs to be shut off with the appropriate allen key count how many turns it takes to close . cheers kop

 

[fixitflav]

I have a valve on the feed/return of the radiator and i cant shut it off. The trv end shuts off but all my radiators have this (as shown in pic) on the other side which i cant isolate with to change radiator. Help please do i need to drain the whole system to remove one radiator?

View attachment 32933

I have Honeywell TRVs, > 20 years old. They're provided with isolating caps. You remove the TRV head, screw on the cap and it closes the plunger. I assume that gives complete closure, like an iso valve, but it's many years since I tried it. Whether more modern ones have this feature, or whether yours does, I don't know.
But unless you can catch the water effectively, or there's nothing it can damage, you might be better off isolating all the other rads then draining the system remotely. That way there's only a small amount of water left in the rad. Also it's easier to catch the water from a drain fitting, so if you have inhibitor in the system you can return it when the job's done.

 

[Scott_D]

Looks like a danfoss LSV
as above use an Allen key

 

[Sanjay Savani]

Yes it is a danfoss valve. Allen key shuts it off. Thanks all for the help. Much appreciated.