ST111
Nov 9, 2008, 09:58 PM
Lennox mod GZ4m3/4-120A-4 Ser 6395M52686 12/95
Board LED shows firing sequence, Gas valve opens, igniter doesn't spark, gas valve closes approx 8 sec. later then retries twice more. The furnace can be ignited with lighter during this sequence and appears to burn normally for approx 8 min. then burner shuts off for several, after which ignition sequence attempts again. Limit switch circuit appears closed (continuity, voltage present), R/O, high limit, airflow all seem OK but spark never generated. Is this a board problem, or am I missing something stupid?
Thanks
Board LED shows firing sequence, Gas valve opens, igniter doesn't spark, gas valve closes approx 8 sec. later then retries twice more. The furnace can be ignited with lighter during this sequence and appears to burn normally for approx 8 min. then burner shuts off for several, after which ignition sequence attempts again. Limit switch circuit appears closed (continuity, voltage present), R/O, high limit, airflow all seem OK but spark never generated. Is this a board problem, or am I missing something stupid?
Thanks