Aprilaire 400M owner manual OPERATING INSTRUCTIONS - MODELS 400, 500, 600, Automatic Mode

OPERATING INSTRUCTIONS – MODELS 400, 500, 600 & 700

The Digital Humidifier Control offers two modes of operation, Automatic or Manual. An explanation of both modes follows. (See Figure A on page 5 for Automatic Mode. See Figure B on page 6 for Manual Mode.)

When in the Automatic Mode, this system offers the following benefits:

•You will always receive the optimum amount of humidity so that your home and its furnishings are always protected from the damaging effects of excess condensation or low humidity during the heating season. The Control automatically adjusts your home’s RH based on the outdoor temperature, increasing the time maximum comfort is maintained.

•Simple operation with few adjustments. The Control eliminates the need to manually adjust the control when outdoor temperature changes. It also eliminates the need to turn the dial setting to “OFF” during the summer season.

DIGITAL HUMIDIFIER CONTROL INDICATOR LIGHTS

Call Dealer for Service: The red light indicates that the humidifier is not operating normally and that service is required.

Change Water Panel: The yellow light indicates that it is time to change the Water Panel in the humidifier.

Humidifier On: The green light indicates that the humidifier is operating normally.

AUTOMATIC MODE

FIGURE A – Automatic Mode

90-1235

Your Aprilaire Humidifier Control is installed in the cold air return duct. During the first heating season, your Humidifier Control needs to be set initially to match your home’s condition. Please follow these steps when adjusting your control (refer to Figure A).

1.Turn the dial setting knob to “5,” which is within the normal range. During the next 24-48 hours it may be necessary to adjust the dial for more or less humidity, depending on your personal comfort and home’s requirements. Refer to TABLE 3 – Operation Guide.

2.During the coldest portion of the first heating season, minor adjustments may be necessary. This is dependent upon your home’s construction. Refer to TABLE 3 – Operation Guide.

The RH in your home will now be accurately controlled to meet your needs and should not need further adjustment during future heating seasons. Make note of the dial setting in the event you temporarily move the knob to “OFF” when performing annual maintenance of your Aprilaire humidifier.

- 4 - - 5 -