I am experiencing problems with a radiator failing to hear up correctly. The longer the heating is on the hotter the radiator gets but adjusting tvr has no affect. I hàve removed head to check pin moving freely, which it does, and also swapping head with radiator which works ok but no change. Inlet valve is open fully and no air in radiator so can only assume tvr valve is faulty somehow. Is it possible that it could be closed or is it more likely a blockage in pipework after valve?
Have you tried adjusting the other radiators lockshield valves, it may just be that the pipework to this radiator has more resistance (bends etc) try closing all lockshield valves fully then open 2-3 turns, Leave the problem radiator valves fully open and see if it's any better. You'll just be restricting the flow through the others and forcing the flow towards this radiator.
I've tried closing all the valves and leaving only the problem one open. This does make it marginally warmer but no where what it should be. Since my last post I have fully drained the system, removed the radiator and flushed through to clear. I also replaced the tvr valve as a precaution. Unfortunately when the system was filled it made no difference at all!
The only conclusion i can come to is that, as the inlet pipe is never hot, the pipe must be kinked or severely blocked. The radiator after the problem one is an extension so I wonder whether on installation that the pipe work was damaged.
Can you think of any way to test this theory other than knocking hole in wall? Suppose I could take of radiator before and problem one, then flush water through one before to see if water comes out at inlet for problem one?
Didnt change other valve but appeared to be fully opening and closing when checked. The pipe work is 10mm. Didn't completely think through whilst system was drained but did prove there was flow between the tvr end of the faulty radiator and the next one although didn't check inlet between one before and problem one.