Carrier Error Code 23: Pressure Switch Fault
Warning: Your Carrier furnace has detected a pressure switch fault, which prevents it from starting for safety reasons. A professional HVAC technician is needed to diagnose and repair the issue.
How to Fix Carrier Code 23
- Step 1: Check the air filter. A severely clogged filter can sometimes restrict airflow enough to trigger a pressure switch fault.
- Step 2: Visually inspect the vent pipes (both intake and exhaust) outside your home for any obvious obstructions like snow, ice, or debris. Safely clear any blockages you can reach.
- Step 3: If the problem persists after checking the filter and vents, contact a qualified HVAC technician to diagnose and repair the issue.
How to Reset Carrier Code 23
- Turn off the furnace power switch, usually located on or near the unit.
- Turn off the circuit breaker for the furnace. Wait 30 seconds.
- Restore power at the breaker and flip the furnace switch back on.
- Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.
What does 23 mean?
The Carrier 23 error code, indicated by a specific blinking pattern on the unit's LED, signifies a problem with the pressure switch circuit. This switch is a crucial safety component that verifies proper venting before allowing the furnace to ignite. When the furnace induces draft, the pressure switch should close, proving that exhaust gases will vent properly. If the control board does not see the switch close, it will display error code 23 and shut down the unit to prevent potential hazards.
Affected Models
- Performance Series Furnace
- Comfort Series Furnace
- Infinity Series Furnace
- Performance Series
- Base Series Furnace
- Performance Boost Furnace
- Performance Boost 95 Furnace
- WeatherMaker 8000
- WeatherMaker 9300
- Infinity 80
- WeatherMaker Furnace
- 24ABC6 Air Conditioner
- 25HBC5 Heat Pump
- Performance Series Heat Pump
- Infinity Series Furnace
- Infinity Series
- Base Series
- Comfort Series
- Infinity Series Heat Pump
- Comfort Series Heat Pump
- Infinity 20 Heat Pump with Greenspeed Intelligence
- Comfort 80 Gas Furnace
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Pressure Switch | — | — |
| Inducer Motor | 326461-756 | — |
| Control Board | HK42FZ004 | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| 11 | No Previous Error | Info |
| 12 | Blower On After Power Up | Warning |
| 13 | Limit/Rollout Fault | Critical |
| 14 | Ignition Lockout | Critical |
| 21 | Gas Heating Lockout | Critical |
| 22 | Abnormal Flame | Critical |
| 24 | Secondary Voltage Fuse | Warning |
| 31 | High Stage Pressure Fault | Warning |
| 32 | Low Flame Sense | Warning |
| 33 | Limit/Rollout Switch Lockout | Critical |