lukewarm radiator

[coldshowerkid]

Hi

one of my radiators has never been the hottest, but its seems to be getting worse, its always the last to warm up and at best is lukewarm and cold at the bottom. This is a downstairs radiator and is fitted with a drayton thermostatic valve. The feed pipe at roasting hot.

Questions
1,is the radiator slunged up, can I test for this?
2, is the valve not working correctly (its set at max), is there anyway to manually open the valve fully, or test the valve operation.

hope you can help

thanks

 

[twgas]

It might be sludged but there are other things to do/check first.
Remove the trv head and check the pin is free to move - push with a flat tool of some kind.
Make sure the lockshield is open.
Turn off the other rads , leaving just the problematic one on for a while to hopefully push out an airlock..

 

[coldshowerkid]

hi

thanks for the quick reply. i have never taken a valve off. what does the pin and the lock shield look like,

thanks

 

[kevplumb]

View media item 11368
pin is under the white bit

 

[twgas]

View media item 11368
pin is under the white bit

and lockshield is the other end of the rad.