I have a Lennox G26 with a Johnson Controls pilot control module #G776RGD-11. The furnace blower comes on and there is spark but once the pilot light comes on it almost immediately goes out. I have already replaced the flame sensor but getting the same results. I have read in other forums that the Johnson Controls module is many times the culprit but is there a way for me to test the module before I spend the money on a replacement? Are there any other reasons the furnace would be acting like this?
Check that your control module is well grounded so that the rectifyer rod signal can be received.
Clean up the pilot assembly/ burner surface metal immediately around the flame rod while you are at it.
Make sure that the flame rod is enveloped by the pilot flame.