CARRIER DIAGNOSTIC REFERENCE STATUS LED — SHORT + LONG FLASH CODES DOC CARRIER-23
Carrier furnace: Code 23 — Pressure Switch Did Not Open
YOUR LIGHT: 2 SHORT + 3 LONG FLASHES — MATCH IT ABOVE
Professional repair
What does code 23 mean on a Carrier furnace? Official: obstructed pressure tubing or a pressure switch stuck closed.
GOOD NEWS: THE FIRST CHECKS ARE FREE AND TAKE MINUTES.
Try these first — in this order
Inspect/clear the tubing.
1Check: Obstructed pressure 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
Pressure Switch
Always match parts against your model's parts list — part numbers vary within a series.
Applies to
58STA · 58STX · Bryant 310/311/312 series · Payne PG8M series
Different Carrier generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Verified against Carrier 58STA/58STX Installation & Service Instructions (1106202L), p.37/48
Last verified 2026-07-06 · how we verify