I’ve bled every radiator in the house, made sure the system is filled, taken the thermostatic valve head off and checked it seems to push down in the same way a perfectly functional one does. The pipe gets hot to the rad but water doesn’t seem to flow in. Valves are relatively new Drayton TRV so shouldn’t be an issue there. Anything simple I’m missing before I pay a call out charge on a boiler engineer?

Turn off every other radiator in the house, heating on, then release trapped air in the cold rad. It sounds like it’s air locked. Had this happen with the kitchen rad after taking it off. Nothing would get hot water to it, until I turned the rest off, then bled it. Check other rads as you turn back on, and bleed them.

Should the bleed valve be at the same end of the rad as the water goes in? Only thing I’ve noticed that is different but not sure if it makes any difference.

Will try that Fossy, thanks.

Usually at the top, at one end. Can’t say I’ve paid much attention to which end it’s on, but turning off all the other rads will force any air lock through the one.

Fossy you bloody genius! Thanks.

Nice one. I did it many years ago, then forgot when my kitchen radiator wouldn’t get hot just a few years ago. Lot’s of head scratching, swearing, then ‘remembered’.

PS we have one rad that get’s air in it, the rest don’t, so keep an eye on that one and bleed it over then next day or two.

Glad fossys advice worked as I was going to suggest the same. Shutting all the other rads forces water/air through the problem radiator. If the radiator reverts to being cold after you open the thermostatic valves, you should research how to balance your system using the lockshield valves (and keep notes on how many turns you adjust each valve incase you mess it up and want to put it all back!)

The lockshield doesn’t need to be very much open to allow the rad to get hot.

Are both valves open?

The lockshield doesn’t need to be very much open to allow the rad to get hot.

Correct, but if someone has fully opened a lockshield vale closer to the boiler, the hot water will take a shortcut and the radiators after will only get hot if the thermostatic valves shut off the closer radiators.