Have a new construction house, and lived here about 2.5 yrs. Turned on my furnace last night worked fine. This morning, it kept turning on then kicking off with no burners coming on.
I noticed the red light was flashing 3 times. Looked up some info and pulled the hose off and noticed the part it plugs into on the fan was all corroded.
What causes this? Is this from the A/C? Everything was fine last year. I do have a whole house humidifier, but no problems last season.