Goodman ComfortNet Eb0, Eb1 and Eb3 in cooling: why an airflow code appears while heating still works

What Does Error b0, b1, b3 Mean?

Read them apart. The b3 entry is the only airflow condition of the three. Goodman describes it as the circulator blower motor operating in a power, temperature or speed limiting condition, and lists blocked filters, restrictive ductwork, undersized ductwork and high ambient temperature as the causes. The b0 entry says the motor is not running when it should be, and b1 says the control module has lost communication with the motor. Neither of those is a duct problem, and grouping all three sends the diagnosis to the wrong place. Applies to: Goodman and Amana variable-speed air handlers with an integrated control module reporting motor codes on a seven-segment display and through a ComfortNet thermostat These codes belong to the air handler integrated control module, and the seven-segment display alternates characters, which is why written transcriptions vary between readers. Furnace and outdoor unit codes on the same ComfortNet system come from separate tables. Owner-safe checks: Check the filter and replace or clean it according to the equipment instructions, because blocked filters are on the published cause list. | Confirm that supply registers and return grilles are fully open and unobstructed. | Record whether the code appears in cooling, in heating, or in both, and whether the blower ran at all. | Note how warm the space around the air handler gets, since high ambient temperature is listed as a cause of the limiting condition. Qualified technician: Any work on motor power leads, motor control leads or the integrated control module is inside an energised cabinet and is service work. | Duct static pressure measurement and duct sizing assessment need instruments and belong to a technician.