Aprilaire 1850 Dehumidifier User Manual


 
TROUBLESHOOTING
Technical Support is available Monday through Friday, 7:00 a.m. to 5:00 p.m. CST, at (800) 334-6011. Use the guides on the following pages to
identify and correct system faults. Contact Technical Support before replacing the unit or any components and for additional troubleshooting.
DIAGNOSTIC CODES
When an error occurs, the Diagnostic Code along with SERVICE REQUIRED
will be displayed on the control screen.
TABLE 4 – Diagnostic Codes
Diagnostic
Code Failure Mode Action Reset
E1 Internal Humidity or
Temperature Sensor
Open or Shorted
1. Check the connection between the sensor board and control board.
2. If connection okay, replace sensor board, Part No. 5460.
Cycle Power
E2 High Refrigeration
Pressure
1. Verify that the fan works, the backflow damper swings freely and there is no blocked or restricted
ductwork.
2. If the fault persists, call Technical Support.
Cycle Power
E3 Model 76
Remote Control
Communication Loss
1. Check connections between Model 76 and dehumidifier control board. Terminals should be fully
inserted and secured in the control board and Model 76 control terminals.
2. If connections are correct and secure, turn off the dehumidifier and remove the Model 76. Use a
short section of 4-wire cable to reconnect the Model 76 to the control board. Turn the dehumidifier
back on and increase the dryness level setting on the Model 76. If the dehumidifier turns on, the
problem is with the wiring between the dehumidifier and control.
3. If the dehumidifier does not turn on, call Technical Support.
Self-Correcting
E4 Insufficient Capacity 1. Check the frost sensor connection at the power board. Terminal should be fully seated on the
power board pins.
2. Remove the side access panel and verify that the sensor is secured to the suction line.
3. If the sensor is connected and secured to the refrigeration line proceed to the next step.
4. Reset the fault by cycling power to the dehumidifier.
5. Turn the humidity setting down (below room/home humidity level) to make a dehumidification call.
6. Allow the fan and compressor to run for approximately 10-15 minutes and then enter diagnostic
test mode by simultaneously pressing the UP ARROW and MODE buttons for 3 seconds. The LCD
will display the temperature measured by the internal sensor while also displaying AIR SAMPLING
and ON, the humidity measured by the internal sensor while also displaying %RH and ON, and the
frost sensor temperature while also displaying ON. Scroll through these values and by using the
UP/DOWN arrow buttons.
7. Record values and call Technical Support.
Cycle Power
E5 High Temperature
Thermistor Failure
1. Check the high temperature sensor connection at the power board. Terminal should be fully seated
on the power board pins.
2. Remove the side access panel and verify the sensor is not damaged and connected to the
refrigeration line coming from the compressor.
3. If the sensor is connected and secured to the refrigeration line, it may need to be replaced with
Part No. 5456 – contact Technical Support to confirm.
Cycle Power
E6 Low Temperature
Thermistor Failure
1. Check the low temperature sensor connection at the power board.
2. Remove the side access panel and verify the sensor is not damaged and connected to the suction
line.
3. If the sensor is connected and secured to the refrigeration line, it may need to be replaced with
Part No. 5455 – contact Technical Support to confirm.
Cycle Power
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