Carrier gas furnace blows cold air
This is my first post here. I am a Home Do-it-yourselfer-So be gentle...
My 10-12 year old Carrier gas furnace (Model # 58ED 050131CA) has had an intermittent problem. It will blow warm air for a few minutes until house is up to the set thermostat temperature, then after the flame is out the blower keeps going until I turn the tstat down all the way. When reset with tstat it will work for a couple cycles then do the same thing. Last Fall it did the same thing and I found that the electronic igniter plate was carbonized. I removed the carbonization and it has worked for 5 months. Do I need to replace this plate or is it another part such as a sensor or circuit board that I need to look into?
Any suggestions are welcome-thanks!