Hi i got a question i do volunteer work for a church and I've fixed many of furnaces before but they always used a pilot light. this one I'm trying to fix now uses Electronic Ignition and the igniter was clearly bad. I replaced it and now it lights but after about 25 to 30 seconds it shuts down. Then restarts the proses and when its burning its working correctly. What senses the flame? because it acts like its not sensing the heat and keeps retrying to light.Thank you.
There should be a flame sensor that looks like a small spark plug, it just needs to be cleaned with emory cloth. If it doesn't have a seperate sensor, the igniter is the sensor, was it replaced with an exact replacement? What is the furnace brand and model?