I have a Carrier gas furnace with an automatic ignition system. Intermittently, the furnace stops working. When I look inside the top door, the igniter is firing. If I remove the top door and use a grill lighter, the pilot ignites immediately, so gas is flowing. Any ideas?.
This is the spark type ignition, right? With this type of ignition device the “sparker” will light the pilot then sense the flame and allow the main valve to open. Some cleaning needs to be done and adjustments checked or this problem will worsen to the point of a dangerous situation should someone stick a lighted flame in the burner box! Have a qualified repair person clean and service your furnace immediately.