Carrier furnace code 13: Limit Circuit Lockout
Try DIY first, then call a pro
What does code 13 mean on a Carrier furnace? A limit, draft safeguard, flame rollout, or blocked-vent switch stayed open longer than 3 minutes → lockout. Auto-resets after 3 hours. Root causes = see code 33.
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
Same first moves as code 33: filter and vents.
Recurring lockouts need heat-exchanger and venting inspection. DIY part cost: $5–25 — a pro visit for this class of fault typically runs $150–350.
What causes it (in order of likelihood)
- Everything under code 33 (airflow/vent restrictions), sustained 3+ minutes DIY-CHECKABLE
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 13 mean on a Carrier furnace?
A limit, draft safeguard, flame rollout, or blocked-vent switch stayed open longer than 3 minutes → lockout. Auto-resets after 3 hours. Root causes = see code 33.
How do I fix Carrier furnace code 13?
Stop troubleshooting and arrange a technician visit. Don't reset any switch. If it returns, call a technician; if a CO alarm sounds, leave and call from outside.
How much does it cost to fix Carrier furnace code 13?
A dirty filter may be inexpensive to correct, but recurring lockouts can call for venting, blower, or heat-exchanger inspection. The price depends on which switch opened and why.
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 13 · Payne furnace code 13
Verified against Carrier 58STA/58STX Installation & Service Instructions (1106202L), p.37/48 — “auto-reset after 3 hours. See code 33”
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.