The short answer
A Bryant furnace in Northern Virginia tells you what’s wrong with a blinking amber light behind the small window in the lower door, and on some boards a small three-digit display too. Count the flashes: short ones are the first digit, long ones the second. Most codes point at something you can see. 31 and 32 are the pressure switches, which usually means the vent or the condensate drain. 33 is the limit circuit, which usually means a clogged filter or weak airflow. 34 means the flame didn’t prove, and the flame sensor is the usual suspect.
What you’ll notice
- The small fan on top (the inducer) starts and hums, but the burners never light.
- The burners light for a few seconds, then shut off, and the furnace tries again.
- The blower runs but the air coming out is cool.
- The light behind the window blinks a pattern and pauses, or the display shows a code like 33.1.
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How to read the code
Bryant furnaces have one of two kinds of control board. One has only an amber light behind the small window in the lower door: short flashes are the first digit and long flashes are the second, so 33 is 3 short and 3 long, then a pause before it repeats. The other has the same light plus a small display that shows three digits, like 33.1: the first two are the flash code and the third narrows it down. A steady light is normal, no light at all means no power at the board, and rapid flashing means the line voltage polarity is reversed. Both boards in Bryant’s current manuals keep the code through a power cut, but some older furnaces erase it, so count it before you flip the switch.
Every Bryant furnace code
These come from the status code tables in Bryant’s 915SB and 916SA installation manuals. The display boards add a third digit (31.2, 31.3), and the meaning of the first two stays the same.
Swipe to see all columns →
Swipe to see all columns →
| Code | What Bryant’s manual says | What to do |
|---|---|---|
| Steady light | Normal operation | Nothing |
| Rapid flash, 10.1 | Line voltage polarity is reversed | Call: it needs wiring work |
| 11 | No previous code stored | Nothing |
| 12, 12.1 | The blower came on after power up, or a heat call was on at power up | Wait: it clears itself after about 90 seconds |
| 13, 13.1 | Limit lockout: a limit switch stayed open more than 3 minutes | Check the filter; the board retries after 3 hours |
| 14, 14.1 to 14.3 | Ignition lockout after 4 tries, or the flame kept dropping out | Call: often the flame sensor, igniter or gas supply |
| 21, 21.1 | The gas valve is getting power when it shouldn’t | Turn the furnace off and call |
| 22, 22.1 | Flame sensed when there shouldn’t be any, which points at a leaky or stuck gas valve | Turn the furnace off and call |
| 23, 23.1, 23.2 | A pressure switch didn’t open: stuck closed, or the tube is blocked | Call |
| 24, 24.1 | The low-voltage fuse on the board is blown | Call if a new 3-amp fuse blows again |
| 31, 31.2, 31.3 | The high-heat (secondary) pressure switch didn’t close or reopened | Check the vent ends and the condensate drain |
| 32 | The low-heat (main) pressure switch didn’t close or reopened | Same checks as 31 |
| 33, 33.1 | A switch in the limit circuit opened: a limit or a rollout switch | Filter and registers first; a rollout trip is a call |
| 34, 34.1 to 34.3 | Ignition proving failure: the flame wasn’t sensed, or was lost | Usually the flame sensor; call |
| 45, 45.1 to 45.3 | Control failure | Cycle the power once; if 45 comes back, the board is replaced |
| 46.1 | A momentary loss of power | Nothing, unless it keeps happening |
13 and 14 are lockouts: the board stops trying for 3 hours, then resets itself and tries again. Bryant’s instruction for 45 is the same on both boards: cycle the power, and if 45 repeats, replace the control.
What you can safely check
- Count the code and write it down before you touch anything.
- Pull the filter. If you can’t see light through it, change it. Our filter guide covers which one to buy.
- Make sure the lower door is on tight. Bryant wires a switch to it, and the board gets no power with the door off.
- Go outside and look at the white PVC pipe ends. Clear leaves, snow or ice from around them, and don’t push anything into the pipe.
- Look at the condensate hose and pump beside the furnace. A full pump that isn’t running is your lead.
- Turn the furnace switch off for 30 seconds, back on, and let it try once.
What not to do
Never jump or bypass a safety switch to get heat back. Each one is there to stop the furnace from burning gas when something is wrong, and the wrong thing is often exhaust, which carries carbon monoxide. Bryant’s manual says the rollout switch, a button on the burner box, must never be jumpered, and its cause has to be fixed before anyone resets it. The board’s fuse takes only a 3-amp automotive fuse; a bigger one lets a short burn the wiring. Never tape the door switch down to run the furnace with the door off. If you smell gas, don’t flip any switches: leave the house and call your gas company or 911 from outside.
What a technician does
We pull the stored fault from the board’s memory (the display boards keep the last 7), so a code that came and went still shows up. Then we measure instead of guessing: the draft at the pressure switch with a manometer, the flame signal in microamps, the temperature rise across the furnace, and the gas pressure. That tells us whether it’s the drain, the vent, the airflow, the flame sensor or the board.
What it costs to have us look
A repair visit starts with a flat $99 diagnostic, and you get the price of the fix before we touch anything. Our Bryant page has more on the Bryant equipment we work on. Our heating check is $67 per system, through December 31: furnace, heat pump or boiler.
Going deeper: Bryant code 31 and 32, the pressure switch, Bryant code 33, the limit circuit, the Bryant flame sensor, how to reset a Bryant furnace and the Bryant Evolution thermostat. Bryant is part of Carrier, and codes 13, 14, 31, 33, 34 and 45 mean the same thing on both, so our Carrier furnace code list reads the same way. Other brands are on our error code and warning light guide.
Every code meaning here comes from Bryant’s own documents: 915SB installation instructions and 916SA installation instructions.
Call or book
Call (703) 997-9757 and tell us the code you counted, or book online from goswiftpro.com/cookiesoffer and a box of warm cookies comes with the visit. Rated 5.0 stars across 1,138 reviews on Google, Angi, Yelp, the BBB and Facebook, Virginia Class A license 2705192276.
Questions people ask
What do the lights on a Bryant furnace mean?
The amber light flashes a two-digit code: short flashes are the first digit and long flashes the second. A steady light is normal, no light means no power at the board, and rapid flashing means the line voltage polarity is reversed.
How do I reset a Bryant furnace?
Count the code first. Then turn the furnace switch or breaker off for 30 seconds and back on. Lockout codes 13 and 14 also clear on their own after 3 hours. If the code comes back, the cause is still there.
What does code 33 mean on a Bryant furnace?
A switch in the limit circuit opened, either a limit switch or a rollout switch. Check the filter first. If it stays open more than 3 minutes, it becomes code 13 and the furnace locks out for 3 hours.
Are Bryant and Carrier furnace codes the same?
Mostly. Bryant is part of Carrier, and codes 13, 14, 31, 33, 34 and 45 mean the same thing on both. The label inside your furnace door has the exact list for your model.
How much does it cost to have a Bryant furnace code checked?
The visit starts with a flat $99 diagnostic, and you get the price of the repair before any work starts.
