I have an AMANA high efficiency gas furnace that lights and kicks on for a few seconds, then shuts off and repeats lighting again. I believe it's a problem with the intake pipe that is becoming filled with water, and flooding something. When The intake and exhaust pvc pipes come out the top of the furnace, and travel upwards to the outside of the house and 90 off. When I remove the intake pipe, a good amount of water comes out.
Anybody have any ideas?