Last Revised: 1/30/25
Your Aprilaire whole-home humidifier is one of the best investments you can make for indoor comfort and air quality. It’ll keep your family comfortable through those long, dry winters, protect your home’s woodwork and furniture, and help everyone breathe easier.
But, like any piece of home equipment that runs indefinitely, your Aprilaire humidifier needs some attention to keep performing at its best.
If you’re looking for answers to your whole-home humidifier maintenance questions, you’ve come to the right place.
What Maintenance Does Your Aprilaire Humidifier Need?
Many of the maintenance steps you’ll need to take care of depend on the specific model (and type) of humidifier you had installed. Aprilaire’s humidifiers are split into two main categories, each with its own maintenance approach: bypass models (600, 620, 700) and the steam model (800).
Some maintenance is routine and DIY-friendly, while others typically call for professional expertise. Let’s first take a look at what needs to be done for bypass humidifiers.
Jump to steam humidifier maintenance (Aprilaire 800 model)
Maintaining Your Aprilaire Bypass Humidifier (Models 600, 620, 700)
Aprilaire’s bypass models work by evaporating water through a special panel as warm air from your furnace passes through. Maintaining bypass humidifiers is more about regular attention than complex repairs.
Annual Bypass Humidifier Maintenance (Start of Heating Season)
Before the heating season kicks into full gear, you’ll want to make some time for a few maintenance tasks. If you have a VIP Membership with Mattioni, these tasks are all included in one of your two annual HVAC tune-ups. For those homeowners confident in their handyman skills, we’ll still show you how to tackle them yourself.
Replacing the Water Panel
This is the most important maintenance task. The water panel (also called an evaporator pad) is where the humidifying takes place. It gets saturated with water, and air passing through it picks up moisture. Over time, minerals from your water build up on the panel, clogging it and reducing efficiency.
When you see the Change Water Panel indicator light blink, you know it’s time to change the water panel.
Start by turning off the power to your furnace and shutting off the water supply to the humidifier. Remove the front cover by pressing the tabs at the top and bottom, and carefully pull out the plastic feed tube from the distribution tray. The water panel will slide out, and you can now slide in your new Aprilaire water panel.
Snap everything back together, push the feed tube back into place, and replace the cover.
Turn the control knob past 7 to the Test/Reset position. It will click into place, and the Humidifier On light will start to blink. Finally, turn the control knob back to its original RH setpoint.
This is a detailed process that should only be handled by those with experience working on home systems, so if you’re not comfortable taking it on yourself, it’s best not to risk damaging any of your equipment. A licensed HVAC technician can come to your home to assist with your water panel replacement and give you peace of mind that the job will be done right the first time.
Cleaning the Distribution Tray
While you’ve got the water panel out, take a good look at the distribution tray. This is the component that spreads water evenly across the top of the water panel. Mineral deposits love to accumulate here.
Lightly scrape off any crusty buildup, being careful not to damage the synthetic fabric liner inside. For stubborn deposits, soaking the tray in white vinegar or a lime-removing solution also works well. Just be sure to rinse the tray thoroughly before reinstalling it.
Inspecting & Clearing the Drain Line
Remove the drain line from the bottom of the humidifier and gently flex it in a few spots to loosen mineral deposits. Run water through it under pressure to flush it clean. If it won’t clear properly, it’s easier to replace it than to deal with clogs down the road.
Checking Water Supply Connections
Make sure all your water line connections are snug and leak-free. Check the plastic feed tube by gently flexing it and looking for cracks or wear. If it shows signs of damage, replacing it is recommended. These tubes are inexpensive and replacing them prevents leaks.
When to Call a Professional for Your Bypass Model
Some repairs are best left to the pros. Humidifier maintenance is a detailed process that should only be handled by those with experience working on home systems, so if you’re not comfortable taking it on yourself, it’s best not to risk damaging any of your equipment. A licensed HVAC technician can come to your home to assist with your water panel replacement and give you peace of mind that the job will be done right the first time.
Maintaining Your Aprilaire Steam Humidifier (Model 800)
The 800 is Aprilaire’s steam humidifier, and it works completely differently from the bypass models. Instead of evaporating water through a panel, it boils water using electrodes to create steam that’s injected into your ductwork.
The steam humidifier is generally lower maintenance than bypass models (there isn’t a water panel or distribution tray that needs to be replaced). Instead, you’ll be maintaining the steam canister.
Annual Steam Humidifier Maintenance (Start of Heating Season)
Steam Canister Replacement
The steam canister should be replaced once per heating season. Inside the canister are two electrodes that electrical current flows between, heating the water to its boiling point and creating steam. Over time, minerals from your water coat these electrodes, reducing efficiency until the canister needs replacement.
Your 800 model has a notification light that will let you know when it’s time to change the canister. When you see this light, turn off the power to your humidifier and let it cool completely (the water inside can be over 200°F).
Once the unit has cooled, remove the front cover, disconnect the steam hose, and unscrew the canister. Install your new canister with a fresh O-ring to prevent leaks, reconnect everything, and restore power. The green indicator light should be solid when everything’s working properly.
Drain Line Maintenance
Just like the bypass models, make sure your drain line is clear and flowing properly by disconnecting the tube, gently flexing the line to loosen buildup, and running water through it to clear the buildup.
The 800 model automatically drains weekly to flush minerals, but hard water can still lead to accumulating buildup that causes efficiency and performance problems.
Checking Water Quality & Mineral Buildup
Your local water quality (well water or city water) makes a big difference in how quickly your canister will accumulate mineral buildup, lose efficiency, and need replacement. It’s wise to conduct a water quality test once per year (included in a Mattioni VIP Membership).
When to Call a Professional for Your Model 800
Steam humidifiers are more complex than bypass models. If you’re experiencing issues beyond basic canister replacement (such as electrical issues or steam distribution problems), that’s when to call in an expert. These repairs require specialized knowledge of both your HVAC system and steam and steam humidifier operation.
Mid-Season & End of Season Maintenance: Bypass & Steam Models
In the middle of winter, it’s smart to do a quick check-in with your humidifier. With the system running, verify that water is flowing properly and that you’re getting the humidity level you want in your home. If your home feels dry or you’re seeing condensation on windows, you might need to adjust your humidistat settings.
When spring arrives, and your humidifier has served its purpose for the year, it’s time to shut off the water supply to the system until next winter.
Signs Your Aprilaire Humidifier Needs Maintenance
Your home will tell you when your whole-home humidifier needs attention. Here are the telltale signs:
- Your indoor humidity gauge is reading low even though your humidistat settings haven’t changed.
- You see white dust settling on furniture near your HVAC vents, or there’s visible mineral buildup around the humidifier itself.
- Water is pooling around the base of the humidifier, or you notice dampness where there shouldn’t be any.
- The unit is making unusual sounds like buzzing, humming, or clicking noises that you haven’t heard before.
- Your heating bills have crept up without explanation, which usually signals efficiency has dropped.
- You catch a musty or stale smell coming from your HVAC system.
If you’re seeing any of these signs, don’t panic. They’re your cue to give your humidifier some attention before a small issue becomes a bigger problem.
Hard Water Considerations for Greater Philadelphia Homeowners
If you live in an area with particularly hard water, you might find yourself replacing steam canisters and other components more frequently than the annual recommendation. The minerals in hard water coat the electrodes faster, reducing efficiency at a quicker rate and potentially shortening the system’s lifespan.
Some homeowners choose to install a water softener specifically to extend the life of their humidifier, along with other plumbing systems like water heaters. If you’re wondering if your home could benefit from a water softener, talk to a Mattioni professional about whether it makes sense for your situation.
Get the Most from Your Aprilaire Investment
Your Aprilaire whole-home humidifier is built to last, and with proper maintenance, you can expect reliable comfort year after year.
Depending on your skillset, the maintenance we’ve covered here may seem well within your wheelhouse, or it may seem overwhelming. With Mattioni’s VIP Membership, all of your humidifier maintenance will be handled during one of your two annual maintenance appointments.
Remember, maintaining balanced humidity isn’t just about comfort. It protects your home’s wood floors, trim, and furniture from the damage caused by dry air. It helps your family breathe easier and can reduce respiratory infections during cold and flu season.
At Mattioni, we’ve been serving homeowners since 1948, and we’ve seen firsthand how well-maintained Aprilaire systems perform season after season. Our team is always here if you need guidance or professional service.
Do you prefer to have the experts handle your HVAC and indoor air quality system maintenance? Schedule your humidifier tune-up with Mattioni today by calling (610) 400-8510 or by booking your appointment directly online. We’ll make sure your Aprilaire is ready for another season of reliable service, so you can focus on enjoying your comfortable home.
