Carrier Furnace Code 15
Soft lockoutShown as: 1 short flash, 5 long flashes
Blower motor lockout. The variable-speed blower failed to reach 250 RPM, or failed to communicate with the control within 30 seconds of being switched on, in two successive heating cycles. Auto-resets after 3 hours.
Manual wording: “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.”
Documented for: 58MVP, 58UVB and other variable-speed two-stage Carrier furnaces
Likely causes, most common first
- Failed blower motor or motor control module
- Loose or damaged blower motor wiring/communication harness
What you can safely check yourself
- Check that the blower door is fully seated - the door switch removes power to the blower
When to call a technician
A variable-speed blower motor fault is a technician job; the motor, its module, and its harness all have to be tested.
A Carrier furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Troubleshooting Guide - Variable Speed, Two-Stage Gas Furnaces (Form 58-06T) (Carrier, 58MVP, 58UVB and other Carrier variable-speed two-stage gas furnaces (replaces 58MVP-10SM)) · checked 2026-08-25