What It Means
Pressure switch failed to close or reopened during operation.
Bryant Furnace
Bryant Furnace Error Code 31
Troubleshooting guide for the Bryant Furnace system fault 31.
Possible Causes
- Inducer motor failure or reduced speed.
- Blocked, leaking, or disconnected pressure switch tubing.
- Restricted vent pipe or flue blockage.
- Faulty pressure switch or incorrect LP gas pressure.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
New to this code? Click to see why this happens
Full Diagnosis
Pressure Switch Did Not Close or Reopened. If open longer than 5 minutes, inducer shuts off for 15 minutes before retry. Check venting, inducer, switch, tubing, combustion air, wind, and inlet gas pressure if LPGS is used.
All Recorded Causes
Check inducer motor speed and operation. Inspect pressure switch tubing for blockage or leaks. Test pressure switch with manometer. Verify vent system is clear and properly sized. Check inlet gas pressure if using LP gas.
Verify Before Replacing Parts
- Confirm the exact Bryant model family and furnaces context before acting on a generic code description.
- Walk the entire heating sequence in order instead of jumping straight to the reported code, watching for check inducer motor speed and operation.
- Verify each safety device and prove where the sequence stops under live operation, including whether inspect pressure switch tubing for blockage or leaks.
- After the correction, run the system long enough to confirm the furnaces fault does not return under normal load.
Still unsure about this fault?
ACLogics walks you through Bryant Furnace diagnostics step-by-step — so you confirm the cause before swapping parts.
