Recently had to replace the original ignition control in a Pulse G21Q3-60-1. It was failing to send consistant 24V to the gas valve resulting in no start or premature flame out. The original control was GC3 part 52J18. Replaced with Lennox part #60J0001 which is a Johnson Control #891. It's running fine. However during the burn the green light flickers rapidly and randomly--it is not .5sec off, .5sec on indicating Low flame sense as it says on the front of the unit. After burn, the light is solid green. Is it normal for this control to have flickering green light during burn? If not does anyone have an idea of what it means especially in view of the fact the furnace is functioning normally now??
It's also interesting I was successful with the old HeatCraft control to measure 2.2microA in series with the flame reticulation sensor--so I knew that wasn't the problem. Because of the flickering light on the new control I checked the microamp reading--I get no reading with the VOM in series and furnace won't run!--I tried to VOM's--same result--hook up the sensor wire again and it runs fine and LED continues random blinking.
Furnace is running great but don't understand the random blinking light and inability to check the sensor as I was with the old control? Any observations would be greatly appreciated. Thank you