Gravity Hot Water air lock

[thesafetyman]

This probably has appeared in the past, but i cant see it anywhere.
I have a gravity hot water system which started going wrong about 2 weeks ago.
I believe there is air in the system (the boiler kettles all the time so its always producing air).
I have tried banging the pipes, sucking the air vent in the loft (dont try this, it gives you bad stomach).
There are no vents i can see.
Anyone got any ideas on how to properly get the air out?
There are quite big horizontal runs.
I plan to replace the boiler and whole system in summer, so all these problems will go, i just want to get through the cold (cooler) months!
Thanks
thesafetyman

 

[Soggy_weetabix]

You could try removing the boiler stat phial & 'boiling' up the h/w circuit.

 

[Lagerkhan]

One way is to connect a hose to mains tap or whatever and push other end of hose down the cold feed pipe from tank in roof and turn on mains pressure

All water and air will come back round system and out of vent pipe into the same tank and then out of overflow pipe.....guaranteed to work everytime