Baxi solo overheating

[Fraba]

Hi recently drained central heating system to add radiator. Refilled - bled rads, pump and various vents in airing cuboard.

Fired boiler but after a minute there was a banging sound from boiler/flow return pipes? then overheat light comes on and boiler cuts out. Heat seems to go partially up the flow (few meters).

Thinking airlock but tried draining and refilling twice already and no joy!

Any help would be greatly appreciated thanks

 

[seco services]

is the pump running ?

 

[compheat]

Is there a motorised valve installed, and is it in the open position??

 

[Fraba]

Pump appeared to be working but i didnt check for voltage. Possibly naively i assumed everything should be working as there were no problems before i drained. Didnt see any motorized valve however it may be hidden. Couldnt understand the heating vs cylinder coil? and had a thermostatic valve on coil linked to a sort of cylinder stat? no heat was getting any where near these pipes though

 

[Boilerman2]

if everything was working prior to draining then it is logical that the draining & refilling MUST be playing a part in this fault I would sugest there is an Airlock in the flow & return between the boiler and the airing cupboard, look for manual air vents in high level pipe work

 

[seco services]

sounds like your talking about a tap stat.

 

[Fraba]

Thats the one. Couldnt find vents in high level pipe. Going to drain down again and put some in see if i can get it going! Thanks