Page 14 of 16 / IM 1171-3
Diagnostics
Problem & Possible Solution
No Display
• Check the power connections and power voltage level
• Replace unit if power is okay.
No Temperature Signal
• Be sure the termination and wiring is correct and the
controller is set up properly. Make sure the “Override/
Reset” button is not stuck down.
• Replace unit if all checks are okay.
Override/Reset Not Working
• Measure the resistance to ground at the sensor output
terminal (Term. 4). When pushing the Override Button, it
should show a short. If not, replace the sensor.
No Fan Voltage Signal
• Be sure the termination and wiring is correct and the
controller is set up properly.
• Replace unit if all checks are okay.
No System Voltage Signal
• Be sure the termination and wiring is correct and the
controller is set up properly.
• Replace unit if all checks are okay.
De-humidification Not Working
• Adjust the System Mode to DHUM and check terminal
DH for voltage.
• Change the RH setpoint above and below the ambient RH
to prove the output contact.
• Replace unit if it still doesn’t work.
Occupied Not Working
• Verify that this terminal is in a powered circuit. Measure
the voltage to ground at the occupied terminal (U). When
pushing the Occupied Button (<2 secs), it should read
close to 0 volts. When you lift the button it should read
high volts.
• Replace unit if it still doesn’t work.
“Err” shown on the screen
• This indicates that the temperature and humidity sensing
element has failed.
Problem & Possible Solution (Continued)
FAN key does not change Fan Mode
• Check to verify FAN is not locked out in Programming
Mode Menu Page P6.
MODE key does not change System Mode
• Check to verify Mode is not locked out in Programming
Mode Menu Page P7.
Up or Down key does not change Setpoints
• Check to verify Set points are not locked out in
Programming Mode Menu Page P11.
Solid Man goes away after 20 seconds
• Occupancy Request was not acknowledged by Main
controller, check wiring of Status Signal from controller.