112
Supply VFD Comm Modbus communication fault.
Check Modbus wiring and connections.
Verify Modbus address.
Verify Min and Max settings of the VFD to
the MUA board settings. Go to
Factory
Settings > Unit Options > Blower
Config > VFD Freq Limits
.
Master ROM CRC
Software mismatch.
Contact technical support.
Clogged Filters
(optional)
Input from filter airflow switch.
Clean or replace filters.
Refer to
Compressor Comm Communication Error.
Check wiring from Compressor VFD to
compressor.
Furnace Float
Input signal from the furnace
condensation float switch is active.
Verify pipe connections are not clogged.
Verify the pipes are draining.
Check for shorted wires.
Replace float switch.
Electric Heater Fault Voltage input is lost while the electric
heater is active.
Check electric heater wiring to board
connector J7 pin 10.
Verify all other wiring is connected
properly.
Check Fuse(s).
RH Sensor (Space,
Intake, Discharge)
One of the Relative Humidity (RH)
sensors are not working.
.
HMI “x” Revision
Wrong
Software mismatch.
Contact technical support to flash the
appropriate software.
HMI Config Error
HMI is not connected, or HMI is assigned
incorrectly.
Install HMI or change HMI address using
bottom 2 buttons on HMI. Refer to
Configuration Menu” on page 30
.
Compressor VFD
Off
Compressor controller is set in the Off or
Hand On position.
Verify that the compressor controller is
set to the Auto On position.
DF Faults
DF faults are communicated from the
compressor drive to the HMI.
Troubleshooting Chart” on page 113
.
Problem
Potential Cause
Corrective Action