One Cold radiator

[gwa15]

I have one cold radiator. It is not the furthest from the boiler. I have tried bleeding air out of it but as far as I can tell only water comes out. When I do this the 2 pipes leading to the radiator get hot but the warmth does not spread beyond the valves. When I stop bleeding, the pipes get cold again. It is the newest radiator in the house (4 yrs old). Problem seems to have started when I turned the radiator valve off once but this may be a coincidence. NB noticeable that one valve turns much less than the other - not sure if this is design or likely fault?
Any advice gratefully received. thanks

 

[HERTS P&D]

Turn the other rads off and see if it heats up. Has the system being balanced?

Andy

 

[WabbitPoo]

If the pipes upto but not beyond the rad get hot then the valve(s) must be faulty or the rad is full of sludge.

 

[Ray84]

Yeah im with the last poster, feel the pipe up to the rad on either side. if one sides hot then its probably the TRV could possibly be sludged but more than likely the trv's sticking or broken could you unscrew the head on the thermostat to see if it helps? should only be hand tight

Ray

 

[Morris40]

take the head off the TRV and you'll see a pin, see if you can push the pin down ( don't use your hand though ) it is most likely stuck closed

 

[gwa15]

Thanks for replies so far.
Have turned all other rads off - no effect.
Valves are not thermostaticaly control (assume that is what TRV means??) but are simple hand turned on/off.
There is no pin to push down once head of valve removed. So would I be in assuming that it is either completely broken valve or sludge and best to get expert help in?
Thanks

 

[Morris40]

if heat is getting to valve well i.e nice and hot but nothing past valve at all it really sounds like a faulty valve, if it was sludge the rad would still get fairly hot all around except at the bottom as this is were the sludge would sit, so if the rad is bled and you get heat around the top half only it most likely will be sludge but no heat anywhere it most likely will be stuck valve