Carrier and Bryant 31 Error Code: Pressure switch did not close or reopened
Updated October 2026 · Sourced from Carrier and Bryant documentation
🛑 Turn it off and call a licensed pro
Carrier and Bryant 31 means different things on different series:
- Carrier 59SC5A single-stage 4-way multipoise condensing gas furnace (Series 1 and 2): A pressure switch did not close or reopened. If the low pressure switch stays open longer than five minutes the inducer shuts off for 15 minutes before a retry. The label lists wind, a restricted vent, a blocked condensate drain, low inducer voltage and disconnected pressure tubing among things to check.
- Carrier 59TP6A two-stage variable speed ECM multipoise condensing gas furnace (Series 2, and Series 3 80-20, 100-20, 120-22): The high-heat pressure switch input failed to close on a call for high-heat, or opened during high-heat. The HPSR relay may be defective.
- Bryant 926TC two-stage variable-speed ECM multipoise condensing gas furnace: Minor 6 is an open secondary pressure switch (HPS). Minor 7 means high heat only for the next cycle because the HPS failed to close in 75s when moving from low to high heat.
Is it safe to keep running? No. Turn it off and get it checked. Call a licensed technician. The label lists restricted venting, condensate drainage, inducer and pressure switch faults, which are combustion safety checks.
31 at a glance
| Code / how it shows | Meaning | Applies to |
|---|---|---|
| 31 Status LED flashes: first digit is short flashes, second digit is long flashes | Pressure switch did not close or reopened | Carrier 59SC5A single-stage 4-way multipoise condensing gas furnace (Series 1 and 2) |
| 31 Status LED flashes: first digit is short flashes, second digit is long flashes | High-heat pressure switch or relay did not close or reopened | Carrier 59TP6A two-stage variable speed ECM multipoise condensing gas furnace (Series 2, and Series 3 80-20, 100-20, 120-22) |
| 31 Also: 31.6, 31.7 Status LED flashes: first digit is short flashes, second digit is long flashes; display shows 31.6 or 31.7 | High-stage pressure switch (HPS) fault | Bryant 926TC two-stage variable-speed ECM multipoise condensing gas furnace |
Check this first
Only steps a homeowner can do safely. Do not open electrical panels or the burner area.
- Look outside at the furnace vent and intake pipe ends. Make sure snow, leaves or a nest are not blocking them. Look only, do not touch the pipes.
- Look at the condensate drain line and trap (if you can see it without removing any panel) for a clog, kink or standing water.
- Turn the furnace power off at the switch or breaker, wait one minute, then turn it back on to see whether the code returns.
🛑 Stop and call a licensed pro if
- Call a licensed technician. The label lists restricted venting, condensate drainage, inducer and pressure switch faults, which are combustion safety checks.
- Call a licensed technician. The pressure switch, relay and venting are combustion safety items.
- Call a licensed technician. Pressure switch and venting checks are combustion safety work.
- You smell gas. Leave the house, do not touch switches, and call your gas utility from outside.
- Flame rollout, limit or pressure switch codes that come back after one reset.
- Anything involving the control board, gas valve, flame sensor, igniter or venting.
- A carbon monoxide alarm sounds. Get everyone outside and call 911 or the fire department.
Safe first steps for any Carrier and Bryant code
- Count the LED flashes through the blower door window before you switch anything off. Cutting power can clear the code.
- Replace or clean the furnace air filter.
- Check the thermostat: correct mode, set above room temperature, and fresh batteries.
- Make sure the furnace power switch and breaker are on. If the furnace has locked out, turning the power off and back on once restarts it.
- Make sure the gas valve is in the ON position, following the lighting instructions on the furnace label only.
- On high-efficiency furnaces, look at the outside vent and intake pipes for snow, ice, leaves or nests (look only, do not take pipes apart).
Sources: Carrier 59SC5A Installation, Start-up, Operating and Service and Maintenance Instructions, Fig. 62 Service Label, p.67; Carrier 59TP6A Installation, Start-up, Operating and Service and Maintenance Instructions, Fig. 63 Service Label, p.73; Bryant 926TC Installation, Start-up, Operating and Service and Maintenance Instructions, Service Label (Status Code Table), p.56. Codes are series-specific, so your unit's own manual is the final word. Reviewed October 2026.
Shaun Cain · Certified HVAC & Refrigeration Technician · Ask an HVAC technician
Related Carrier and Bryant codes
LED off : Status LED off (no power to control)LED on : Status LED steady on (normal)Rapid flashing : Rapid flashing LED (reversed polarity)11 : No previous fault code stored12 : Blower on after power up13 : Limit circuit lockout14 : Ignition lockout21 : Gas heating lockout22 : Abnormal flame-proving signal23 : Pressure switch did not open24 : Secondary voltage fuse is open33 : Limit circuit fault (limit or rollout switch open)