Hi,
My 9-year-old Bryant 355MAV shut off after heating for about 15 minutes, even though the house is only about 60 degrees. I've been trying to figure it out all day.
If I turn the furnace off, then back on, it will start up OK, the inducer motor starts running, the burners light up and the blower runs for a good 15 minutes or so.

Then I start seeing an error code in the little LED lights. Most of the time it is 31, but one time it was 32. The whole thing shuts down. It will try to start up again a couple of times, but the ignition won't light the burners. After a couple of tries it quits all together until I turn the furnace power off and start from scratch.

My owner's manual says the 31 means a high pressure switch fault that indicates high pressure switch is closed at call, or in low heat, or fails to close after call, or opens in high heat. And it says to check for plugged condensate drain, water in vent piping, improper pressure switch wiring or pressure switch tubing connections or failed or out of calibration pressure switches.

Water in the vent piping sounded like the most likely candidate, as we just had a big sleet/snow storm yesterday. I went outside and there is definitely moisture around the opening of the vent (exhaust )tube, but the tube is curved, and I can only see in a couple of inches, not sure how to check the elbow.

As far as the condensate drain, I have no idea what this is.

I am not a mechanic, but can do simple fixes. I'm sure I can check the vent pipe if someone has any idea how I can do it, and also check this drain. Beyond that, I'm not sure.

Thanks so much for any help at all. I hate to spend my kids' Christmas money on a repair call unless I really need to.

Could be a few different things really. Inducer could be failing, pressure switch can have moisture inside etc etc.

I assume you have a high efficiency furnace?

Hi,
Thanks for the response. Yes, it is a high efficiency.
I turned off the circuit breaker and restarted the whole thing. It ran for about an hour, though the air coming out of the register didn't seem to be as warm as usual. Then it stopped even though the house was not at temperature yet. It has since cycled on and off a couple of times for 10 minutes or so at a time.
So odd.
Something could be failing. The inducer motor seems to be taking several seconds to get up to speed, don't know if that is usual.
I was just outside looking at the exhaust vent and air was blowing out pretty strongly at me. Smelled a little like exhaust air, I guess that is normal.

Is there Two pipes outside?

Hi Hvac

How's it going?

Oops, Hi HVAC
Yes, 2 pipes
The intake vent also looks clear. That one points down towards the ground (both come out the side of the house around waist high) Hard to see how it could be plugged, but I did look inside it.

I was sitting watching my furnace run. I noticed it ran for a long time, 30 minutes or so, in the green LED mode. Then it speeded up the blower fan and went into the yellow LED mode, which I think is high heat? That seems to be what triggered it to shut down.

I got the 31 or 32 code, sorry forget which, the burners went off, everything turned off, then about 3 minutes later it started up. Still running I think, about 10 minutes later.

House is up to 62 degrees, which is the warmest it has been all day. But the heat coming out of the registers seems to not be as warm as usual.

Have you looked at the chart to see what the codes mean?

I'm guessing that you're furnace is 2 stage variable speed blower.

Hi,
Yes, the codes 31 and 32 are similar.
My owner's manual says the 31 means a high pressure switch fault that indicates high pressure switch is closed at call, or in low heat, or fails to close after call, or opens in high heat. And it says to check for plugged condensate drain, water in vent piping, improper pressure switch wiring or pressure switch tubing connections or failed or out of calibration pressure switches. 32 is high pressure switch fail.

I'm sorry. I'm getting sleep deprived. 32 is low pressure switch fault. 31 is high pressure

Ok,do you see both pressure switches?

The furnace says it is a Bryant plus 90 high efficiency (natural)
Condensing gas furnace

The pressure switches are the twin round pancake like things, I see them.

Ok, do you see the rubber tubes on both of them?

Locate where the tubes plug into the furnace and remove the tube and try to clean the hole out,you will need a paper clip or something small.

I see a black rubber looking tube that goes into the side of one of them, and a u-shaped rubber tube where one end goes into the front of each of the round pancake things. They have little clamps at the point where the rubber meets the switch.

I take the tube off at just the end that goes into the furnace? I'll go look and see if I can find that. Then I just take a paper clip and clean out the end of the tube, or should I take it off both ends and blow through it?

Leave it connected at the pressure switch,remove the tube where it plugs into the header plat on the furnace.

OK, going to do that now. I'll be right back.

I'm going to take you through a few steps and see if we can figure it out.

Any luck?

Hey Hvac
I did what you suggested, took the black rubber tube off the furnace, and water poured out of it, and also came out of the furnace front. It is still coming out, so I want to go back down there, I have it going into a little water bottle.
I was surprised to see water coming out. Did I do something wrong?

At least the water is nice and warm.

OK, I think it is done draining. I think at least 3 cups of water came out of the front of the furnace.
Do I plug it back in now?

No,you unhooked the drain not the pressure switch tube,but that's OK

Try blowing through the tube you have unhooked,is it restricted?

The pressure switch tube is about a 1/4 inch rubber tube. Lets skip the pressure switch for now. Hook the drain back up.

Oh,
I tried to blow through it. I heard a tiny pop, then nothing. I can't blow through it.

What is the other end connected to?

It comes out the back of the pressure switch and goes into the front of the furnace right at the bottom of the main compartment, it goes into a flat black plastic plate that is on the front of the furnace.
I didn't see another tube that went from the pressure switches to the front of the furnace. Maybe I'm not understanding what you mean.

I'm looking at my diagram of the furnace. The tube come sout of the back of the pressure switch, goes to the side of the heat exchanger I think it is and plugs into the wall that is at the front of the furnace, right at the bottom, inside the main compartment. I wish I could upload a picture so I could show you.

Do you see the inducer fan? Located in the top compartment of the furnace.

You can upload a photo,that may help.

Is that the big round plastic cover right behind the inducer motor? I see it

OK, let me geta good photo, b right back

Do you see any small tubes going to the inducer fan?

Hi,
I have my photo, don't see how to upload it. Let me go look at the inducer fan again. I don't remember a little tube.

Hit the go advanced button at the bottom, you cadd attachments