York - Johnson Controls (System Lockout)

[RedmondMTB]

I have a York P2DPD12N natural gas furnace that just experienced a system lockout, one flash of the diagnostic LED. It happened during the morning warm-up after a cold night. The control board is a Johnson Controls G951ADB-1403.

Is there any method to put the control board into diagnostic mode to learn exactly what is locking out the system?

[rundawg]

I have a York P2DPD12N natural gas furnace that just experienced a system lockout, one flash of the diagnostic LED. It happened during the morning warm-up after a cold night. The control board is a Johnson Controls G951ADB-1403.

Is there any method to put the control board into diagnostic mode to learn exactly what is locking out the system?

No there is not. The control is locking out because it does not recognize that the burners have lit.

A qualified tech should be contacted to investigate why that is, and try to remedy the issue.

With the age of this system, it would be in your best interest to have him examine the heat exchanger while he is there too.