HVACopedia

AirQuest · Furnace

31 Pressure switch did not close or reopened

High severity

What the control is telling you

The inducer pressure switch did not prove draft.

Applies to: Carrier/ICP-family two-digit status codes — confirm with the code label on the unit

Likely causes

  • Blocked vent or intake
  • Blocked condensate trap / hose
  • Cracked or disconnected pressure switch tubing
  • Weak inducer motor
  • Faulty pressure switch

Test and repair steps

  1. Check vent and intake terminations
  2. Clear the condensate trap and hoses
  3. Inspect pressure switch tubing
  4. Measure draft with a manometer against the switch rating
  5. Replace inducer or switch as indicated

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Source: Carrier/ICP status code label — verify per model. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.