Aprilaire 62 Safety And Installation Instructions Manual page 14

SYMPTOM
Humidifier operates only in "Test/Reset" mode.
• If outdoor temperature is greater than 60°F or less than
-30°F, the humidifier control will only operate in the
"Test/Reset" mode (for 1 minute).
• If the humidity level in the home is higher than the humidifier
control knob setting, the humidifier control will not operate
the humidifier.
TROUBLESHOOTING PROCEDURE
• Measure the resistance of the ODT 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. Reconnect the
ODT sensor leads. If the resistance value does not match the
temperature value, replace the ODT sensor.
• Make sure that the ODT sensor is mounted completely
outside the house on the north, east or west side of the
house and out of direct sunlight (Automatic Mode only).
• Make sure that the ODT sensor is located at least 3 feet
away from all exhaust vents (Automatic Mode only).
• If ODT sensor is mounted in the fresh air intake duct, make
sure that the sensor is no more than 3 feet from the outside
wall (Automatic Mode only).
• Make sure the "R" and "C" terminals are wired per enclosed
wiring diagrams.
• If control setting was changed from Automatic to Manual,
power to the control must be disconnected, then restored.
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SYMPTOM
Humidifier operates constantly.
• If the humidity level in the home is less than the humidifier
control knob setting and there is a continuous fan call or heat
call (depending on setup), the humidifier control will operate
the humidifier until the humidity level is higher than the
humidifier control knob setting.
TROUBLESHOOTING PROCEDURE
• Set Blower Activation switch to "OFF."
• In the "Test/Reset" mode, verify that the humidifier turns off
after 1 minute.
• Check the ODT sensor resistance and location, as instructed
on the previous page.
• Rotate the humidifier control knob counterclockwise to the
"OFF" position, and observe whether the humidifier turns off.
If the humidifier still operates in the "OFF" position, perform
the following:
1. Check the wiring diagram for correct humidifier control
installation.
2. Remove the wires from the "H" terminals on the
humidifier control. If the humidifier continues to operate,
replace the solenoid valve.
• Ensure humidifier control is installed per instructions in
STEP 1 of the INSTALLATION section.
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