HVAC Code Lookup

Bryant Furnace Code 31.2

WarningShown as: 3 short flashes, 1 long flash; 31.2 on the display

Open secondary pressure switch (HPS) - the high-heat pressure switch did not close, or reopened, when the control needed it.

Manual wording: “31 2 Open secondary pressure switch (HPS)”

Documented for: 912SE

Likely causes, most common first

  1. Restricted vent or blocked intake/exhaust termination
  2. Plugged condensate drain
  3. Excessive wind at the vent
  4. Disconnected or obstructed pressure tubing
  5. Defective inducer motor or low inducer voltage
  6. Defective pressure switch

What you can safely check yourself

  • Go outside and check the furnace intake and exhaust pipes for snow, ice, leaves, or a nest and clear any blockage
  • Check the condensate drain line and trap for a clog
  • Replace a dirty air filter

When to call a technician

If the vents are clear and the drain is open, the inducer, pressure switch, or tubing needs a technician. Never jumper a pressure switch.

A Bryant furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

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