Carrier furnace code 23: Pressure Switch Did Not Open
Professional repair
What does code 23 mean on a Carrier furnace? Official: obstructed pressure tubing or a pressure switch stuck closed.
Before you touch anything: the six signs that mean stop troubleshooting and call a pro →
GOOD NEWS: THE FIRST CHECKS ARE FREE AND TAKE MINUTES.
Try these first — in this order
Inspect/clear the tubing.
Switch replacement. DIY part cost: $30–60 — a pro visit for this class of fault typically runs $150–350.
What causes it (in order of likelihood)
- Obstructed pressure tubing DIY-CHECKABLE
- Switch stuck closed TECH
Parts referenced by this code
Always match parts against your model's parts list — part numbers vary within a series.
Questions about this code
What does code 23 mean on a Carrier furnace?
Official: obstructed pressure tubing or a pressure switch stuck closed.
How do I fix Carrier furnace code 23?
These parts are inside the furnace, so there's no homeowner check. A technician should inspect the tubing and test the switch; never bypass it.
How much does it cost to fix Carrier furnace code 23?
Cost depends on whether clearing the tubing solves it or the switch needs replacing. A technician's inspection determines which.
Related symptoms
These symptoms can appear alongside this code. The link is an association, not a diagnosis, and code meanings vary by brand, model and control.
Applies to
58STA · 58STX
Different Carrier generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Same control platform, same code: Bryant furnace code 23 · Payne furnace code 23
Verified against Carrier 58STA/58STX Installation & Service Instructions (1106202L), p.37/48
Last verified 2026-07-06 · page updated 2026-10-07 · how we verify
Related Carrier furnace codes
These codes use the same status led — short + long flash codes system.