b0 Indoor blower not running when it should be

What the control is telling you

The outdoor unit sees that the indoor circulator blower is off during a call that needs airflow, so the outdoor unit will not run.

Applies to: Communicating 2-stage condensers and heat pumps with the PCBHR104 or PCBHR105 outdoor control (7-segment display): ASXC16/18, GSXC16/18, DSXC16/18, ASZC16/18, GSZC16/18, DSZC16/18

Likely causes

• Indoor blower motor or motor wiring problem
• Communication error between the indoor and outdoor units
• Indoor control fault

Test and repair steps

1. Warning: Kill power to the outdoor unit before touching wiring, the compressor terminals or the control.
2. Read the indoor unit's 7-segment display for its own code (for example Eb0-Eb9) and follow that code first.
3. Check the blower motor power and 4-wire communication harness between the indoor control and the motor.
4. Verify the indoor control is working and talking on the network; repair any wiring faults.
5. Repair or replace the indoor blower motor or indoor control as found.

Models that show this code

24 models in Goodman/Amana ComfortNet ASZC/GSZC/DSZC

Other codes on the same units

• 08 No line voltage
• 09 Low 24 V control voltage
• A2 Outdoor air temperature sensor fault
• A3 Outdoor coil temperature sensor fault
• b9 Indoor airflow lower than requested
• d0 No shared data on the network
• d1 Invalid shared data on the network
• d2 System mismatch - indoor unit cannot supply required airflow