Hello, I have a Bryant plus 80 2spd. Furnace [basement installed] that's aprox. 9 years old. It doesn't seem to be working properly [rarerly shuts off, constantly cycling] when it gets real cold and is flashing a code 31. The blower wheel [motor] in the front has been noisy for a while and I plan on replacing it. Not sure what it's called [low speed, hi speed etc.. ] could this possibly be my problem? I've replaced the flame sensor twice and the igniter once since I've owned it. It will reach the set temp. but it seems like it's always running. Looking it over I noticed holes [rotted out] in the exhaust pipe, it's about a 3 foot section that has a "T" in it for the hot water heater. I took it off and rapped it in duct tape for now until I can replace it. Will this be safe until I can replace the pipe? I don't know how long we've been breathing carbon monoxide... :(. Any advice would be appreciated.

First off, need to replace any rotted pipe immediately. There should be a place on the inside of the furnace cover that tells what the code 31 means, or in the insruction booklet. Please look for this and let me know what code 31 means. If you can get your hands on a vacuum gauge, you can test your inducer to see if it is pulling sufficient vacuum.

Check your filter too ! Open limit would cause a constant fan as well on most carrier furnaces

Find specs for designed temperature rise on the unit label and measure (difference between supply and return air temps = temp rise). If it is too high you have an airflow problem.

first off, need to replace any rotted pipe immediatly. There should be a place on the inside of the furnace cover that tells what the code 31 means, or in the insruction booklet. Please look for this and let me know what code 31 means. If you can get your hands on a vacuum guage, you can test your inducer to see if it is pulling sufficient vaccum.

Thanks for the quick reply. Will the duct tape be safe [not melt etc.] until I can replace the pipe? It's only a few feet away from the furnace. I know it's used for duct, but wasn't sure about exhaust.

I checked the code and it says:
#31: High heat press switch or relay did not close/reopen
Ck for: control relay may be defective, refer to #32

#32: Low heat press draft safe guard aux limit did not close/reopen
With a long list of possibilities, one being defective blower motor or capacitor.

With the blower being noisy [bearing] I thought maybe this could be my problem.
Thanks again.

check your filter too ! Open limit would cause a constant fan aswell on most carrier furnaces
The filter is new, not sure what an open limit is. I know very little about furnaces :(. I'm in the auto industry, thing haven't been real great lately and I can't really afford a furnace guy right now. I've had so many bad experiences with home repair, I thought I might try and resolve this myself. If anyone has any auto related questions I may be able to help you out :D.

There is an electrical box with a switch and a plug [that my cond. Pump is plugged into] mounted on the side of the furnace. I shut off this switch and turned it back on. The furnace shut down and came back on. It worked normally, and finally shut off on it's own [without me having to turn the tstat way down] for the first time in a long time. Does this shed any light on my problem? TIA

I cannot speak for others on here but I can't say that I know of any one that uses duct tape on duct work anymore. Aluminized Tape would work but by no means should you consider it a permanent or even short term fix. If your flue pip is rotted/rusted out, patch it for the night and replace it first thing in the AM.

I cannot speak for others on here but I can't say that I know of any one that uses duct tape on duct work anymore. Aluminized Tape would work but by no means should you consider it a permanent or even short term fix. If your flue pip is rotted/rusted out, patch it for the night and replace it first thing in the AM.

That is the plan, had the duct tape handy and will replace pipe tomorrow.

My furnace operated normally and no flashing LED for a few hours after shutting off/turning switch back on. Now I notice it's back to running constantly and flashing code #31. Guess I'll have to bite the bullet and call a furnace guy on Monday. Thanks for the replies.

Have you checked the sticker inside the blower door to see what code 31 equates to on your system?

Have you checked the sticker inside the blower door to see what code 31 equates to on your system?

Yea, I put that info in my 5th post. It say's control relay may be defective then refer to #32. There is a long list of possibilities for code #32. Like I said previously, the blower motor in the front is noisy. It looks similar to a car blower with 3 wires coming off it [red, what, blk] to a white connector, mounted with rubber gromments. Is this possibly the inducer motor? It's one of the poss's for code #32. Like I said, I don't know much about furnaces. I know this motor has been noisy for a while, looks like a simple part to replace. The Co. that installed the furnace is local and I'm sure I can get a replacement, just want to make sure I'm getting the right part. Thanks for the replies.

Try this: with the furnace running, nudge the wires connected to the pressure switch(es). If the burners drop out the switch is bad. Watch the status LED for any changes.

Try this: with the furnace running, nudge the wires connected to the pressure switch(es). If the burners drop out the switch is bad. Watch the status LED for any changes.

I tried nudging wires, connections with no change. I checked and made sure the grounds/connections were tight. It has been working fairly normal today, other than the noisy blower, but it hasn't been as cold outside. I notice if I set the stat at 70-71 it shuts off, if I set it to 73-74 it doesn't? It still flashes the code #31 either way. When it gets real cold this thing will run/cycle all night... never used to do that. I'm going to replace the blower motor [inducer motor? ] and see if that makes a difference. It was getting noisy last season and it's getting worse. TIA

If the inducer motor is really noisy, it may be struggling to achieve the proper speed to maintain engagement of the pressure switch(es).

If the inducer motor is really noisy, it may be struggling to achieve the proper speed to maintain engagement of the pressure switch(es).

Ok, thanks. I didn't know what an inducer motor was until I found this site and started reading a bit. I thought it was a low speed blower or something? After searching for a while for a reference on the web [I wasn't having any luck before I posted here] I finally found a manual and can say for sure that it is the inducer motor that is noisy. I'm going to replace this and I'll let you know if it takes care of my problem. Thanks a lot for your help guys.

Update: I bought an inducer motor before the holidays, but didn't install it until yesterday. I got just the motor and after reading here a bit it sounded like I'd have a problem getting the blower wheel removed, so I put it off thinking I would slide through until the weather broke. Well, no such luck, the furnace up and quit the day before yesterday. I did have a problem getting the set screw out, but a little "good" penatrating oil and a quality allen wrench finally did the trick. All is well now and the furnace works better than it ever has! Thanks a lot for the knowledge on this site and for your replies. I would have just called the HVAC Co. to come out and repair it for me, but it's a long story. I'll put it this way, if I did my customers the way they did me, I'd be out of work in a hurry. Thanks again.

Glad its working for you, let us know if any further problems arise. Take care,

Lee