Buderus gb142 revision air vent leak

[Vermont Tom]

I have water coming out of the vent. Looks like a shraeder type valve but I don't think it is. From what I can see from the parts manual is that there is some type of float system in there. Could it be taken out and just cleaned? Or should I just buy a new one. I can't get a good description of the part other than it's just the cap.HAs to be more to it than that. Wondering if anyone has replaced one of these.

 

[BadgerBoilerMN]

The air vent on a GB142 is used for commissioning the system. Once the air out of the boiler it should be shut off. If it leaks at any time after commissioning, it must be replaced for future serviceability.

 

[Sponsor]

 

[Vermont Tom]

The air vent on a GB142 is used for commissioning the system. Once the air out of the boiler it should be shut off. If it leaks at any time after commissioning, it must be replaced for future serviceability.

How does it turn on and off? It just has a plastic screw cap on top. Does it let air out automatically? Should I just leave the cap loose ?