Just checking in,I'll check back shortly to see if you are around.

Hi my friend,
I was wondering if all that water that drained out of the collector box last night when I took off the pressure switch drain tube indicated that maybe the drain trap or some part of the drain tubes were clogged.
Im not sure how to clear out the drain trap.
Just to test this idea, when I got home I took off the same tube again, the one from the pressure switch to the collector box. Again, water flowed out of the tube and the collector box, 2 cups at least.
Then I took the inducer housing drain tube off its drain plug. Nothing came out there.
I am thinking there should not be so much standing water in the collector box, something must be stopping it from draining. Does this sound right to you?
Do I need to go to the drain trap now?

The trap should be flushed at the beginning of each heating season as part of the required maintenance for the unit. If you experienced condensate migrating through the pressure switch tubing, the switch canister may have water inside and will eventually fail. Take the pressure switch off and give it a shake to see if water comes out. If so, I highly recommend replacing it. And, you're correct about water accumulating in the collector box-this is a sign that it is not draining properly.

Sounds like too much water your trap is the white thing at the bottom of you pic. It hangs down into the blower compartment. Take it off and clean it out with water. And the hose coming off that going to the drain clean that out (flush water or blow it out)

Hi,

I think I got it, thanks so much for the invaluable help. Until I found this site, I was really bummed. I just did not have it in my budget for a $300 service call 2 weeks before Christmas. Would have been pretty thin pickins under the tree. Your helpful advice gave me the confidence to do it myself. Now I feel pretty handy.

Couldn't figure out how to get that drain trap out, so I took off the biggest tube, the collector box drain tube I think, and blew a bunch of water through the drain trap. I got a bunch of gunk out and when it seemed clear, I put the tube back on.

Turned on the furnace and it so far seems to be working fine.
The first 10 minutes or so it ran, a gurgling sound came out of the drain tube, but it quit after a few minutes.

KC13, I don't feel confident enough to take the pressure switches off, but since the furnace seems to be running OK, do you think it is OK if I wait until spring to make a preventive service call? Christmas and all that...

Greg HVAC guy, do you work the northern suburbs, like Highland Park? That's where I am. If so, give me your co name and I'll call you then.

Than

The question you must ask yourself is, do I feel lucky? Well do you? C'mon man, you've come this far, check those switches! If you look closely at the pressure switch hoses, they should have labels to identify where they go. The switch assembly mounts to the front of the inducer with two 1/4" zinc-plated screws (yellowish color). Take 'em out, pull the labeled hose off the tee in back, and shake the switch assembly. If you hear water inside, drain out as much as possible and replace the switch assembly as soon as possible. If not, then answer yourself-yes, I do feel lucky!

Well, it is supposed to warm up this weekend, so I guess I could shut the furnace down for an hour or two.
When you take those screws off, the 2 switches and the bracket all come off in one piece? I don't have to take the wires off the front?
If I hear water, I'd drain it out the holes where the rubber tubes connect, I guess?

Yes, the switches are an assembly. If one is bad you replace both. No need to remove wires yet, just the screws and the hose on the back so you have enough movement to detect water if present. Confidence! Or draw a pic, works just as good...