The furnace - Comfort Maker (Super High Efficiency) Model GUH 100 A016 CIN (16 yrs old), Module - White-Rogers 50A55-843 (2 weeks old), Stat - White-Rogers 1F56W-361, Filter - 16x25x4 (2 wks old). This is the 3rd module, original replaced after 14 yrs and replaced again 2 yrs later.
Issue - When stat calls for heat, inducer motor comes on, 20 secs later ignitor comes on and within 10 secs gas valve opens, nice blue flame last 1 sec on goes off (valve closes). Inducer motor stays on for a total of 60 secs, which is 30 secs after the blue flame. Inducer motor shuts off for 5 secs and the cycle is repeated. Continuous flashing of LED is described as Flame sensed >5 secs without gas valve. But I did get flames. Removed flame sensor from above one of the burners, cleaned it with emery cloth and reinstalled. Powered up the main switch and the same events were repeated. Is there a way to check the flame sensor? Thank you in advance.