Can anyone offer any suggestions on a problem I have with a gurgling radiator? There are no other problems with the system and the radiator in question (bedroom) is one of eleven in the house and works perfectly well in terms of heating the room. However, when the system switches on I have noticed a gurgling sound coming from the inlet to the radiator. The inlet is fitted with a TRV although I removed the thermostatic device and replaced it with the manual control knob when the problem occurred, it made no difference though and the gurgling still happens. I have bled the radiator although there appears to be no air present and I am sure there are no leaks in the system as the pressure at the boiler (approx 1 bar) is constant and has not needed to be 'topped up' since the system was installed last year. Thanks for any advice.
Try shutting down all the other rads in the house and run the system with only the problem rad on. If it is an airlock it should shift it.
If the inlets are at the bottom of the rad and you get no air then it cannot be air (gas). I would replace the TRV. Just because you replaced the head the valve is still in there. Some older TRVs cannot be fitted the 'wrong way around'. So check that it goes with the flow. New ones are usually okay to be fitted to either flow or return. Try the other suggestion first - turning off all the others.