Troubleshooting Guide

SYMPTOM

Call Dealer For Service Light Flashing (see Figure M).

TROUBLESHOOTING PROCEDURE

Applies to both Automatic and Manual Operation unless indicated otherwise.

Display Error Code: E1: RH Sensor

Rotate HumidifierControl knob to the “Test/Reset” position. After 5 seconds, the green “HumidifierOn” light will blink, resetting the error. If E1 returns,replacethe Humidifier Control.

Display Error Code: E2: Control Knob

Rotate HumidifierControlknob to the “Test/Reset” position. After 5 seconds, the green “HumidifierOn” light will blink, resetting the error. If E2 returns,replacethe Humidifier Control.

Display Error Code: E3: Outdoor Temperature Sensor

Auto Mode (switch in “AUTO” position)

1.Make sure that the Outdoor Temperature Sensor is properly connected to the ODT terminals on the Humidifier Control.

2.Measure the resistance of the Outdoor Temperature Sensor by removing the leads from the Humidifier Control terminals and measuring the resistance across the wires with an ohmmeter. Confirm the reading with the temperature in Table 1 on page 22. Reconnect the ODT Sensor leads. If the resistance value does not match the temperature value, replace the Outdoor Temperature Sensor.

TROUBLESHOOTING PROCEDURE (CONTINUED)

3.Rotate Humidifier Control knob to the “Test/Reset” position. After 5 seconds, the green “Humidifier On” light will blink, resetting the error. If E3 returns, replace the Humidifier Control.

Manual Mode (switch in “MAN” position)

1.Make sure the ODT terminals are clear of any wires that may short the terminals together other than the ODT sensor.

2.Rotate Humidifier Control knob to the “Test/Reset” position. After 5 seconds, the green “Humidifier On” light will blink, resetting the error. If E3 returns, replace the Humidifier Control.

Display Error Code: E4: Communication

This error applies to systems wired to an Aprilaire Model 8570 Thermostat (see Figure Q) using the “A” and “B” terminals. Rotate the Humidifier Control knob to the “Test/Reset” position. After 5 seconds, the green “Humidifier On” light will blink, resetting the error. If E4 returns, check the wiring between the Digital Humidifier Control and Model 8570 check the connections at “A”and “B” on the humidifier control and the Model 8570. Make sure the Model 8570 is wired and operating properly according to the Model 8570 manual.