Troubleshooting


Display is blank
  • Check circuit breaker and reset if necessary.

  • Make sure power switch for heating & cooling system is on.

  • Make sure wire connections (especially C wire) are secure.

  • Verify the R/Rc slider switch is set up if Rc doesn’t have a separate wire attached.

Heating or cooling does not run
  • When running heat, display will show HEAT ON in lower right of display

  • When running cool, display will show COOL ON in lower right of display

  • If display shows WAITING FOR EQUIPMENT under temperature reading, it is in compressor delay mode to protect the system. Wait 5 minutes to see if the thermostat makes a Heat or Cool call

  • If display does not indicate a call for Heat or Cool or WAITING FOR EQUIPMENT, verify the mode setting, temperature setpoint and room temperature

If the Up or Down arrow is pressed:

  • Upper left of display shows mode setting

  • Upper right shows setpoint

  • Center of display shows room temperature

If the issue persists:

  • Check circuit breaker and reset if necessary

  • Make sure power switch at heating & cooling system is on

  • Make sure furnace door is closed securely

Heat or Aux Heat runs with Cooling
  • Verify there is not a wire attached to W for heat pump systems. See Wiring.

  • For heat pump applications the reversing valve is energized in Heat on some heat pumps and Cool for other heat pumps.

  • Verify that ISU 2060 is set correctly.

  • Verify that no wires are shorted. Look for exposed sections of wire at the UWP.

Heat or Aux Heat runs with no call for heat or cooling
  • Verify display does not indicate HEAT ON, COOL ON or AUX HEAT ON

  • Verify there is not a wire attached to W for heat pump systems. See Wiring.

  • Verify that no wires are shorted. Look for exposed sections of wire at the UWP.

Cannot change setpoint to desired setting
  • Verify the mode setting (Heat, Cool or Auto or Em Heat in upper left of display)

The setting ranges for these modes are:

  • Heat or Em Heat: 32 ºF to 90 ºF (0 ºC to 32.0 ºC)

  • Cool: 50 ºF to 99 ºF (10.0 ºC to 37.0 ºC)

WAITING FOR EQUIPMENT (shown in display under Room Temperature)

The Compressor Protection feature is engaged. Wait a few minutes for the system to safely restart to avoid damaging the compressor.