Gurgling noise in radaitors / Air

[Longclough]

I am wondering if someone can provide some advice on gurgling noise in radiators and bleeding air from CH System.

I find that I am able to bleed air out of my CH system on a regular basis (1 radiator and system bleed points). I can also hear gurgling noise in a couple of radiators with TRVs when the system is running. I notice a rushing water sound in some radiators/pump area when the pump starts/cycles.

All radiators get warm top and bottom and when bleed the colour of the water is clearish (Not at all black). System is open vented with combined F+E (No vent pipe) so this cannot be the cause of the air. I have checked all radiator valves and visible pipework for leaks and cannot see any.

I am considering adding Inhibitor as I have not added any since leaving in the house (4 yrs) but appears there was some in there previously. Is this a good starting point.

I am also getting a banging in my pipework the the central heating is running. It is actually quite annoying, although I expect that this will involve taking up floors to solve. Just thought it may be worth mentioning as well.

Can anyone provide any explanation to the air in my system, also should I add the inhibitor?

 

[libby lou lou]

Are you sure this is air and not gas in your system?.

 

[Longclough]

Thanks for your reply, however I have tried the match trick and didn't get a popping sounds, as the air was expelled from the radiators.

I think the system needs dosing with inhibitor, so I will do that first and see it inproves the situation!