What does the E3 code mean on my Aprilaire Humidifier control?

Thursday, July 14, 2011 by Aprilaire Team
Consumer Comment:

What does "E 3 code "mean?  On my Aprilaire Humidifier control?

Aprilaires' response:

Thank you for contacting us regarding the E3 code. When the E3 code is displayed, it means there is something wrong in the ODT terminals. If you are using an outdoor temperature sensor, you will want to make sure all the connections between the sensor and humidistat are secure. If all the connections are good then the sensor may be bad.

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 ohm meter. Confirm the reading with the temperature in Table 1 on page 22 of the attached installation instructions. Reconnect the ODT Sensor leads. If the resistance value does not match the temperature value, replace the Outdoor Temperature Sensor.

If using a manual mode resistor (blue tag that says "manual mode"), make sure the wires of the resistor are securely in the ODT terminals and that wires are not broken or separated from resistor. If the humidistat has a "MAN" switch as described on page 21, be sure there are no wires that may short the ODT terminals.

After checking all connections and making sure the temperature sensor is reading accurately, 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 control.

If you have any further questions regarding this or any of our products, please feel free to contact our customer service department at your earliest convenience.

Comments for What does the E3 code mean on my Aprilaire Humidifier control?

Monday, October 8, 2012 by Rick:
I have the E3 error because contractor probably ripped off the sensor. I'm going to check, but can the unit run without the sensor? Otherwise I need to order one.

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