Taco zone control shows zone one calling for heat, circ pump running, GB142 is not firing. No error codes. I switch off boiler, wait maybe 5 minutes, switch on and it fires. Had thoughts about jumping out AM10 outdoor reset. Any other ideas? Has not been service since installed almost 3 years ago. Thanks a lot for any help!
You can't just jump out the AM10. It connects to terminals on the boiler that are communicating. If no AM10 is used, the the pump control end switch would go to the "WA" terminals which would fire the boiler to its high limit setting. You could do this to get heat until the AM10 is diagnosed.
I'd jump the end switch terminals "XX" on the pump control first to see if the problem is there. Then check all your connection between there and the boiler.
Does the boiler circ turn on when the firing delay happens? If so, the issue is internal to the boiler.
You can choose to do what you want, but you cannot choose the consequences.