Another air problem

I had to drain my heating system to fit a new 3-port motorised value as the old valve had sprung a leak. This fitted fine and appears to work. However, on refilling the system I appear to have air in the pipes (microbore). The radiators are bled but when the boiler runs for a couple of minutes you hear the air near the boiler (quite loud) and it then cuts off in Overheat mode (Baxi Solo). How can I get rid of this excess air? A colleague has suggested turning the thermostat down and running the pump for 10 minutes with the valve manually open to push the air through the system. However, where is the best place to bleed this excess air? Is this the best solution?

Did you refill properly by opening the 3 port valve to allow water to your rads?
Air vent point near the cylinder, have you bled it there.

Could try bleeding the pump from the centre screw.

To be honest, not sure what position valve was in when I refilled - but the rads appear full and drip when bled from the top, so assuming OK.

Have tried the central screw on the pump - and the air vent near the cylinder also drips when bled.

Is your F/e tank full of water.?.

Should be 100 mm deep when system is cold.

Is there a vent on top of your boiler?

Tank appears fine - not too full, but floating the ball OK.

Can't see a vent on top of boiler. Would this be on the boiler itself or in the pipework?