Carrier 58MVP Error Code 23: Pressure Switch Did Not Open
What Does Code 23 Mean?
Status code 23 on the Carrier 58MVP means the control board detected that a pressure switch remained closed when it should have opened. The pressure switch is a normally-open safety device that closes only when the inducer motor creates sufficient draft. When the inducer stops, the switch should return to its open state.
The most common cause is an obstruction in the pressure tubing — the small rubber or vinyl hose that connects the pressure switch to the inducer housing. Condensation, debris, or insect nests can block this tubing and keep pressure applied to the switch even after the inducer stops. The switch itself can also develop stuck contacts from age or contamination.
While this is classified as a low-severity code on the 58MVP, it still prevents normal furnace operation. A technician should inspect the pressure tubing for blockages, test the pressure switch with a manometer, and replace the switch if its contacts are stuck.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Obstructed pressure tubing | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- When this code appears — pressure switch and tubing inspection requires a technician to test and clear the obstruction or replace the switch
✓ Verified against manufacturer service manual — March 2026