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Lochinvar "out of sequence A and B"

Grega Member Posts: 20
I have 2 CFN1442PM boilers. They were both tied to the same neutral and i would get only one lock out on the sequence. Pulled another neutral to separate. I do not read any voltage on the neutral for either. Heat exchangers are clean. New gas valve on one and all new hSI all around. Made sure no breaks or shorts in wiring. Today both boilers were locked out on out of sequence...


  • Mike_Sheppard
    Mike_Sheppard Member Posts: 696
    Those are Copper Fin II’s, larger ones.

    Flame out of sequence means a flame is being detected when the flame should be off. The gas valves could not be closing. There could be water around/on the hot surface ignitor. The hot surface ignitor may not be turning off (wiring or ignition module problem). In my experience, most of the time it’s been bad ignition modules.

    Make sure the boilers are grounded.

    Here is a picture from the manual.
    Never stop learning.
  • Grega
    Grega Member Posts: 20