What It Means
Brown-out protection is active and actively monitoring incoming line voltage.
Carrier Air Conditioner
Carrier Air Conditioner Error Code 6
Troubleshooting guide for the Carrier Air Conditioner system fault 6.
Possible Causes
- Normal monitoring status — brown-out protection active.
- Check for associated fault code 46 lockout.
- Measure line voltage under load if code 46 occurs.
- Inspect disconnect wiring, lugs, and circuit loads.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
New to this code? Click to see why this happens
Full Diagnosis
Brown Out Protection is Active. This is an informational status, not a fault — it indicates the control's brown-out monitoring circuit is currently armed and watching incoming line voltage rather than reporting a failure. Brown-out protection exists to keep the compressor and outdoor fan motors from running, or attempting to start, on line voltage too low to support them safely, since running a compressor motor on insufficient voltage causes excess current draw and winding heat that shortens its life. Code 6 simply confirms this safeguard is active; it differs from code 46, which is the actual lockout event triggered when voltage drops far enough, long enough, to block compressor and fan operation outright. No action is required for code 6 alone, but if the unit is frequently found sitting in this status or repeatedly progressing to fault 46, a technician should treat it as a supply-quality problem worth investigating rather than an isolated event.
All Recorded Causes
Informational status. Brown-out protection is enabled and actively monitoring line voltage; no repair action is required for code 6 by itself. Confirm the unit is not also logging fault 46, the voltage-drop lockout this protection guards against. If the unit is frequently in this state or nuisance-tripping to 46, measure supply voltage at the outdoor disconnect under running load, inspect wiring and connections for undersized conductors or loose lugs, and check whether other loads on the same circuit pull voltage down during compressor start. Contact the utility company if supply voltage measured under load is consistently marginal rather than a wiring problem on the unit side.
Verify Before Replacing Parts
- Confirm the exact Carrier model family and air conditioners context before acting on a generic code description.
- Confirm filter condition, blower operation, and coil cleanliness before replacing any controls — start by ruling out whether informational status.
- Measure airflow-related readings that match the symptom, such as temperature split or static pressure, and check whether brown-out protection is enabled and actively monitoring line voltage; no repair action is….
- After the correction, run the system long enough to confirm the air conditioners fault does not return under normal load.
Still unsure about this fault?
ACLogics walks you through Carrier Air Conditioner diagnostics step-by-step — so you confirm the cause before swapping parts.
