Humidifier How-To
How to Use the AprilAire 62 Automatic Steam Humidistat
The AprilAire 62 is a digital, automatic humidistat built for AprilAire steam humidifiers, like the 800 series. Like the Model 60, it uses an outdoor sensor to automatically adjust your target as the weather changes — it just skips the water-panel reminder, since steam humidifiers don’t use one. This guide covers day-to-day use. If it isn’t mounted and wired yet, that’s a job for a licensed technician.
At a Glance
15–45% RH
Adjustable range
Set anywhere from 15% to 45% relative humidity, with a 3% differential.
Outdoor Sensor Included
Automatic adjustment
Uses an included outdoor temperature sensor to automatically raise and lower your target humidity as the weather changes.
Built for Steam Humidifiers
Works with
Designed for AprilAire steam humidifiers such as the 800 series, but will run any humidifier with a 24V AC control circuit.
Blower Activation Switch
Built-in feature
Includes a built-in blower activation switch to run the furnace fan along with the humidifier.
Setting Your Humidity Level
This covers using the control once it’s installed. Mounting it, wiring it to your steam humidifier, and running the outdoor sensor wire is an installer-level job, not covered here.
Step 1
Check the display
Confirm the lighted “Indoor Humidity” display is on and showing a current RH reading from your return duct.
Step 2
Set your target
Turn the dial to a number from 1 (Less) to 7 (More), with 4 marked “Normal.” A setting around Normal is a reasonable cold-weather starting point for most homes.
Step 3
Let the outdoor sensor do its job
With the outdoor sensor wired in, the control automatically adjusts your target as outdoor temperature changes, so you shouldn’t need to re-set it through the season.
Step 4
Watch for condensation
If you see moisture on windows, lower your target a step and give it a day to catch up.
Daily-Use Features
Automatic seasonal adjustment
As outdoor temperature changes, the control automatically adjusts your indoor humidity target to help prevent window condensation, without you touching it.
Steam humidifier compatible
Unlike bypass or powered humidifiers, a steam humidifier boils water to add moisture, so this control is built without a Change Water Panel light — there’s no panel to replace. It’s otherwise the same control as the Model 60.
Blower activation switch
A separate OFF/ON switch runs the furnace fan along with the humidifier, so moisture distributes through the ductwork while it’s running. Leave it in the position your installer set.
“Humidifier On” light
Lets you confirm the humidifier is actively running versus sitting idle between cycles.
Common Mistakes to Avoid
- Re-adjusting the setting every time the weather changes — that’s what the outdoor sensor is already doing for you automatically.
- Looking for a water-panel reminder light — steam humidifiers don’t have a water panel, so this control doesn’t include that indicator.
- Setting humidity above 45% expecting a drier result — the unit is designed to operate within its rated 15–45% range.
- Assuming any steam-related maintenance (like cleaning the steam canister) is covered by this control — it only manages the humidity setpoint, not canister service.
Troubleshooting
- Condensation on windows. Lower your target setting a step and give it a day to catch up; if it persists, the outdoor sensor wiring may need to be checked.
- Display is blank. Check that the humidifier and furnace have power. If it stays blank, call us.
- Humidity doesn’t seem to track the display. Confirm the furnace fan is running when the humidifier calls, since the blower activation switch needs to be set correctly for your system.
- Steam humidifier itself needs service (scale buildup, canister replacement). That’s a maintenance item on the humidifier, not this control — call us to schedule it.
AprilAire 62 Questions
How is this different from the Model 60?
They work the same way — automatic, digital, outdoor-sensor-based — but the 62 is built for steam humidifiers and skips the water-panel reminder light that bypass/powered humidifiers need.
Do I need the outdoor sensor wired in?
It’s how the automatic adjustment works, so we recommend it.
What’s a safe humidity range to run?
The control is rated for 15% to 45% RH. Back off a step if you see window condensation.
Can I call AprilAire directly about the humidifier itself?
Yes — AprilAire’s customer support line is 800-334-6011.
Want It Installed and Set Up for You?
We’ll mount the control, wire it and the outdoor sensor to your steam humidifier, and set a sensible starting target for your home in one visit.
See our indoor air quality services or the How-To Hub.
This guide is general homeowner information and is not a substitute for AprilAire’s own manual or support resources. AprilAire is a registered trademark of Research Products Corporation.
