Annual Summer Shutdown

For Models 400, 400M, 500, 500M, 600 and 600M close the bypass damper, which is a part of the humidifier, with the small damper handle.

Humidifier Control:

Digital Humidifier Control in Automatic Mode (see Figure A): No adjustment is necessary.

Digital Humidifier Control in Manual Mode (see Figure B): Set the knob to the “OFF” position.

Manual Humidifier Control (see Figure C): Set the knob to the “OFF” position.

PERIODIC PREVENTATIVE MAINTENANCE

NOTE: Periodic inspection and preventative maintenance of your total heating system is important for efficient and safe operation. Your heating contractor can service your humidifier at the same time he services the HVAC system.

All models have a distribution tray above the Water Panel, which should be inspected annually and cleaned of excess mineral deposits. Older models have a granular coating in the distribution tray. Do not scrape the granuals out of the tray. Newer models have a fabric liner in the distribution tray.

WATER LINE INSPECTION AND SERVICE INSTRUCTIONS

WATER

FEED TUBE

OUTLET

COMPRESSION

NUT

ORIFICE

SOLENOID

VALVE

INLET

IN-LINE

STRAINER

INLET

COMPRESSION

NUT

90-1053

1.Disconnect electrical power to the HVAC and shut off water supply.

2.Disconnect the water line at the inlet compression nut.

3.Remove the in-line strainer from inside the inlet side of the valve by using a small nail or wire.

4.Flush the in-line strainer clean or replace with a new strainer, Part No. 4004.

5.Reconnect the inlet water line. Double

Wrench to Prevent Leaking.

6.Disconnect the water feed tube at the outlet compression nut.

7.Inspect the water feed tube by gently flexing it and looking for cracks or signs of wear. Replace tube if it is cracked, brittle, or has been damaged.

8.Inspect the orifice in the water feed tube and make sure the small opening is unplugged.

9.Reconnect the water feed tube. Double Wrench to Prevent Leaking.

10.Remove the drain line from the bottom of the humidifier. If applicable, flex it to loosen any mineral deposits or blockages. Flush the drain line with water under pressure to clear it of any debris, and slip it back onto the drain fitting. If drain line does not flow properly, replace it. Inspect the drain line to make sure it has a constant downward slope and is not flattened or blocked.

11.Turn on water supply and reconnect electrical power to the HVAC.

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400, 600, 400M specifications

The Aprilaire 400 is a high-performance whole-home humidifier designed to enhance indoor air quality and provide superior comfort throughout your living spaces. As part of the Aprilaire family, known for their commitment to creating healthier environments, this model stands out due to its innovative features and advanced technologies.

One of the main characteristics of the Aprilaire 400 is its capacity to humidify homes effectively, covering an area of up to 4,000 square feet. This makes it ideal for large living spaces, ensuring that every room benefits from balanced humidity levels. The humidifier operates seamlessly with the home’s existing heating and cooling systems, requiring no additional maintenance, making it a hassle-free solution for homeowners.

A prominent feature of the Aprilaire 400 is its self-regulating technology. This unit uses a built-in humidistat that senses the moisture levels in your home and adjusts the humidification output accordingly. This ensures optimal humidity—typically between 30% and 50%—which can help reduce issues related to dry air, such as dry skin, irritated sinuses, and static electricity.

Another key benefit of the Aprilaire 400 is its evaporative design, which utilizes a water panel rather than a traditional water tank. This allows for efficient moisture dispersion, as the humidifier draws in dry air, passes it through the water panel, and releases it back into the living space as humidified air. The water panel is replaceable and designed for annual maintenance, promoting long-term functionality and hygiene.

The Aprilaire 400 also incorporates a simple installation process. With compatibility for various heating systems, including forced air and hydronic, it can be integrated into most homes without significant modifications. Its compact design is another advantage, ensuring it can fit unobtrusively in your home, maintaining the aesthetic of your space.

Overall, the Aprilaire 400 whole-home humidifier is a reliable solution for maintaining optimal humidity levels, fostering a healthier living environment, and enhancing overall comfort. With its advanced features, ease of use, and efficient operation, this humidifier is a smart investment for any homeowner aiming to improve indoor air quality and promote well-being.

Aprilaire 600, 400M owner manual Annual Summer Shutdown, Periodic Preventative Maintenance

Models: 400 600 400M