Carrier furnace: Code 15 — Blower Motor Lockout
Professional repair
What does code 15 mean on a Carrier furnace? On the two-stage variable-speed control (58MVP, 58MVB, 58UVB), the blower failed to reach 250 RPM, or failed to talk to the control within 30 seconds of being switched on, in two heating cycles in a row. Official: the lockout auto-resets after 3 hours, and the root causes are the same as code 41.
Same diagnosis as code 41. The official flowchart is a voltmeter test sequence at the motor plugs, so this is a technician visit. DIY part cost: $400–800 — a pro visit for this class of fault typically runs $150–350.
What causes it (in order of likelihood)
- Everything under code 41 (rubbing or loose blower wheel, wiring from the control to the motor, blower control module or motor) TECH
Parts referenced by this code
Always match parts against your model's parts list — part numbers vary within a series.
Applies to
58MVP (Series 170/180) · 58MVB · 58UVB
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 58MVP/58MVB/58UVB Troubleshooting Guide (58-06T), p.7/15 — “BLOWER MOTOR LOCKOUT – Indicates the blower failed to reach 250 RPM or the blower failed to communicate within 30 seconds after being turned ON in two successive heating cycles. Control will auto reset after 3 hours. Refer to status code #41.”
Verified against Carrier 58MVB Service and Maintenance Instructions (58MVB-2SM), p.17 — “Control will auto-reset after 3 hours. See code 41.”
Last verified 2026-09-05 · how we verify
Related Carrier fault codes
These codes use the same status led — two-stage variable-speed (58mvp / 58mvb / 58uvb) system.
| Pattern | Meaning |
|---|---|
| Code 25 — Model Selection or Setup Error | |
| Code 32 — Low-Heat Pressure Switch Did Not Close or Reopened | |
| Code 41 — Blower Motor Fault | |
| Code 42 — Inducer Motor Fault |