Payne furnace pressure switch problems

[danfreeman]

I have a Payne furnace that was installed about 6 or 7 years ago. I woke up this morning to no heat. The induction motor was blowing but the furnace was blinking a code 31 (pressure switch). After checking vents, etc. I bypassed the pressure switch and the furnace works fine. So, it's either a problem with the switch or the switch is legitimately working because of another problem.

If I disconnect the tube that connects the combustion chamber to the pressure switch with the pressure switch otherwise connected, the furnace works great.

So, can someone help me out with some diagnosis? Where should I check next? Is it likely to be the switch itself or something else? And if it's likely something else, what should I be looking for?

-Dan

[HayZee518]

see if there is a "small" air pressure at the tube (or a vacuum) at the tube. if there is none change the tube there may be some crap inside it preventing the switch from "proving air/vacuum)

[danfreeman]

additional info

I pulled the tube going into the blower and quite a bit of water came flowing out. Could this be the issue?

[HayZee518]

could be the proving switch is for air pressure not water. water is preventing the switch from operating.

[danfreeman]

Water build up

Yes. For the moment at least it appears water has been building up instead of getting drained. I drained what was in there and it is working fine. The question at this point is...why is the water not draining through the condensate trap. Probably clogged I guess...I don't see an easy way to remove the trap...argh

Thanks for the help.