40 Direct-Fired Indoor and Outdoor Units • MUA-SVP01A-EN
Diagnostics

SOLUTION: If OAT, RoomT or DAT are such that heat is required

1. Is the outside air temperature (OA Temp), displayed on the BACview remote,
reading 150°F or more?
–Yes . The outside air sensor circuit or the sensor itself is shorted.
Unplug the input jack from the AdaptAire controller. Did the display
change to -40°F or less?‘
– No. There is a short in the controller input. Replace the controller.
– Yes. Disconnect the sensor wiring at the sensor. Connect an ohmmeter
to the sensor. If it is shorted replace the sensor. At 70°F the resistance
should be 10K?. See thermistor output curve for other temperatures. If
it is not shorted, there is a short in the wiring between the sensor and
the input plug. Determine cause and rectify. Refer to Appendix II for a
typical 10K? thermistor output curve.
2. Is the outside air sensor in the direct sunlight?
–Yes . Provide shade for the sensor so the direct sun does not affect it.
–No. Contact factory.

SOLUTION: If setpoints are misadjusted

1. Is the Econmzr Setpoint set for 80°F?
–Yes . The outside air temperature is over 80°F and there should be no need
for heat. If this is not the case, contact factory.
–No. Increase the ECONMZR SP setpoint. See Heating Mode - Energy
Savings Mode 3 section of this manual for more information.
FAULT CODE:Insufficient OA
PROBLEM: The controller has turned off the burner enable output because the
percentage of outside air has dropped below 20% for more than five minutes,
and the unit is in the Heating mode.

SOLUTION:If heat is desired

1. Are the outside air hood filters or bird screen or any associated outside air
ductwork obstructed?
–Yes . Clear obstruction or change filters.
–No. Continue.
2. Are the outside air and return air dampers and actuators working properly?
–Yes . Continue.
–No. Make necessary adjustments and force the unit to recalibrate. See
Calibrate in the Resets Section of this manual.
3. Are the flow measuring station pitot tubes and pressure tubing clear?
–Yes . Continue.
–No. Clean and force the unit to recalibrate. See Calibrate in the Resets
Section of this manual.