Payne Furnace Code 31.4
WarningShown as: Major code 31 on the LED (3 short, 1 long); 31.4 on the display
Loss of pressure before the blower comes on. The pressure transducer does not sense the target pressure, or pressure is out of range for the operating stage.
Manual wording: “31.4 LOSS OF PRESSURE - Before blower comes on.”
Documented for: PG80MSU
Likely causes, most common first
- Improper vent sizing
- Low inducer voltage (115 V)
- Inadequate combustion air supply
- Disconnected or obstructed pressure tubing
- Defective inducer motor
- Defective pressure transducer
- Excessive wind
- Restricted vent system
What you can safely check yourself
- Check the outdoor intake and exhaust pipes for snow, ice, leaves, or a nest and clear anything blocking them
- Replace a dirty air filter
When to call a technician
If the vent is clear, the inducer motor or the pressure transducer needs testing by a technician.
A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- PG80MSU: Installation, Start-up, Operating and Service and Maintenance Instructions (Payne, PG80MSU 80% multipoise gas furnace with 3-digit display and pressure transducer) · checked 2026-08-25