Water Pouring From Thermostatic Valve on Radiator All aspects of plumbing questions and answers, help, tips and information

[botlette]

I turned all the valves off on the radiator yesterday, one thermostat, one .. er, not. Then I took the radiator of the wall.

The thermostat valve started dripping but I didn't have the right size cap, so I used what I had and some PTFE tape. When I went to go and change the cap to the right size earlier the water came _gushing_ out. It eventually stopped but then started to build up from a drip to a slow trickle again.

The valve is off, or at the very least set to '0.' Is it busted? Do I need to replace it or is there something else within the system that isn't right? I obviously have very limited knowledge about what I'm doing, but if the radiator is isolated, where is this water coming from?

Any ideas would be very much appreciated!

[Skid Sprocket]

You should never rely on a TRV to shut the water off. There should have been some kind of cap supplied with the valve to replace the TRV head to isolate the rad.
The other "er" valve is a lockshield valve used to balance the flow to all the rads, when shutting this valve you should count the number of turns to off so that it can be reset exactly as it was.