Goodman Amana ComfortNet GMVC8 Service Instructions Manual page 46

SYSTEM OPERATION
22. Motor Parameters. This condition occurs if the motor
does not receive all the information is requires to oper-
ate or an event occurs that prevents the motor from run-
ning, or the motor fails to start for (40) consecutive at-
tempts. The diagnostic error code for the this condition
is b7. Probable causes are intermittent wiring connec-
tion between the control and motor, an error with the
furnace control, or any of the conditions described in
19, 20, or 21 above.
23. Low Indoor Airflow. This condition occurs if the in-
door airflow falls below a calculated minimum value. The
minimum airflow value is calculated from factors defined
in the shared data set. If the airflow falls below the
calculated minimum, the furnace will continue to oper-
ate with the reduce airflow. If the furnace was operating
at stage, it will stage back to low in an effort to remedy
the condition. The furnace will halt operation if the air-
flow falls to 0 CFM.
The diagnostic error code for the this condition is b9.
Probable causes are blocked/clogged filters, blocked or
restrictive ductwork, or undersized ductwork.
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