Carrier 40MBFQ Owner's Manual page 13

CLEANING, MAINTENANCE AND TROUBLESHOOTING (CONT)
PROBLEM
Unit/System Does Not Work
Cooling is Not Working
Properly
Heating is Not Working
Properly
Unit Stops During Operation
* Diagnostic lights are a combination of lights that will illuminate in the display area on the unit. They are a combination of the lights you see during normal
operation.
Table 3 – Troubleshooting
POSSIBLE CAUSE
• The circuit breaker has tripped or a fuse
has blown.
• Power failure.
• Diagnostic lights illuminate.*
• Voltage is too low.
• The filter is blocked with dust.
• Temperature is not set properly.
• A window or door is open.
• The outdoor unit is obstructed.
• The fan speed is too low.
• The operation mode is in Fan instead of
Cool.
• The filter is blocked with dust.
• Temperature is set too low.
• A window or door is open.
• The outdoor unit is obstructed.
• The Off timer is not operating correctly.
• Diagnostic lights illuminate.*
• Reset the circuit breaker or replace the fuse with
the specified replacement fuse.
• Restart operation when the power is restored.
• Call your service representative.
• Call your service representative.
• Clean the air filter.
• Check the temperature and reset if necessary.
• Close the window or door.
• Remove the obstruction.
• Change the fan speed selection.
• Change the operating mode to Cool or reset the
unit.
• Clean the air filter.
• Check the temperature and reset if necessary.
• Close the window or door.
• Remove the obstruction.
• Restart the operating mode.
• Call your service representative.
13
SOLUTION