QUESTION: Is my circuit board short circuited from the condensate leakage?
FURNACE: Payne Plus 90 Model 398AAZ060120, Series A, approx age is 15 years.
Replaced the igniter lockout control box 3 years ago.
Replaced the external condensate sump pump 4 years ago.
Last month in a cold snap the condensate tube from the pump froze where it exits the house.
Condensate water then overflowed onto the basement floor.
I removed the external condensate sump pump and let the condensate flow directly into a bucket on the floor next to the furnace. (Emptying every 3-4 hours as needed) As soon as the cold snap was over I returned the condensate pump to the system and checked/confirmed for free-flow to the outside. Worked fine.
4 weeks later I noticed rusty colored water on the floor around the base of the furnace. The condensate was not flowing out of the furnace. The furnace started acting strange and not cycling properly.
calls for heat:
1) The draft inducer motor/blower turns on and the igniter/lockout initiates the sparking sequence.
2) The pilot solenoid on the main gas valve “makes” and the pilot burner ignites with an even blue flame about 1.5” to 2” tall.
3) The secondary solenoid on the main gas valve makes contact and the main burners ignite with faltering flames.
4) The secondary solenoid on the main gas valve breaks contact and the main burners go out.
5) The secondary solenoid on the main gas valve makes contact again and the main burners ignite with faltering flames. This cycle goes on for a few minutes as the burner box gets warm. (The igniter/lockout control never stops sparking during this sequence of events.)
6) Once the burner box is fully warmed the main blower comes on and the furnace runs up to set-point.
7) Rusty water is draining out of a black tray below the burner box and into the exterior of the furnace parts inside the front cover and dripping into the lower chamber where the main blower is located.
I shut of the mains power, checked the condensate trap and it was full of rusty water. I removed it and flushed it out with clean water. There appeared to be no moving parts in the trap: no diaphragm valve, no check valve, nothing. NOTE: all ports on the trap flow air/water in any direction – in or out of any port. I don't know if this is normal or not as I cannot locate any info on proper trap operation. I replaced the trap, turned on the mains power and restarted the system.
1) The draft inducer motor/blower turns on but the igniter/lockout does NOT initiate the sparking sequence.
2) The 5-minute cycle times out and the draft inducer motor/blower turns off. End of cycle.
3) No restart unless the mains power is cycled off then on.
4) The draft inducer motor/blower turns on and the 5-minute cycle times out and the draft inducer motor/blower turns off. End of cycle.
So, to sum: Once I cleaned the trap the igniter no longer starts the sparking sequence.
No pilot ignition and no ignition of main burners.