Humidifier Water Panel - Best Time to Change is Now and How To

September 2, 2023

Have you noticed a runny or stuffy nose lately?  How about watery or itchy eyes?

You may think only spring time with its blooming trees and flowers is the cause of your allergies, and you'd be right. But, many of those same symptoms can show up in the fall and allergy sufferers will be miserable.

Ragweed is the most common cause of fall allergies. "Depending on where you live, ragweed-fueled fall allergies can start in August or September and continue through October and possibly November." 

According to accuweather, many regions throughout the United States are taken over by ragweed and mold spores, even when most plants begin to abscise for the winter. 

But you're not here for the weather report; (however unusually warm weather will extend the season for fall allergy sufferers in eastern US), you want to know more about your humidifier water panel:

When to replace it, how to replace it and why you need to change it today...


Because it can help you with your allergies.

And a whole lot more...

Bonus Offer: Download our HVAC Systems Go-to Guidebook as a PDF for free. Easily save it or print for reference anytime.


What is a Humidifier Water Panel?

First time hearing that term? It goes by a few names:

water panel, evaporator pad, humidifier/water filter

The techy description: 

"Water Panel Evaporators are the heart of your humidifier and the component which generates the important humidity to keep you comfortable during the heating season. The water panel slides into the scale control insert and the water distribution tray sits across the top of the panel."

Humidifiers are one of the most effective tools for keeping a building, home, or office comfortable. A whole home humidifier is designed to deliver the correct amount of moisture to your home in every season.

Changes in season or just changes in the weather can bring about dry air that can make you have nosebleeds, headaches, itchy skin, and red eyes. Minimizing the ill effects of dry air will make your home more comfortable. Seasonal humidity levels can affect home comfort.

Many of the best units utilize a humidifier water panel within an enclosure that attaches to your current heater or central air system. It works by mixing water and a forced stream of hot air, which is then distributed through your duct system.

Even if you are not bothered by the dryness of the air during the day, you may notice you sleep better using a humidifier.

Is it Time to Replace Your Humidifier Water Panel?

One question you may be wondering is just how often the humidifier water panel should be changed. Manufacturers suggest most models should be replaced at least once per season. This is because the air being forced through the filter carries dust and other particles, which can clog holes in the mesh when they mix with water. 

The typical water panel (or evaporator pad, or filter) in the humidifier is constructed of an expanded aluminum honeycombed mesh dipped in a ceramic slip (liquid clay). The large surface area of the clay material is perfect for absorbing water. 

iaqsource, your source for indoor air quality, agrees when openings in the water panel become clogged with scale and mineral deposits, they will restrict airflow through the pad and should be replaced. The life of the water panel evaporator will vary with the hardness of the water, the amount of use, and the application. It is recommended the water panel be changed at least once every year depending on air flow.  

It's a good idea to plan your replacements in advance. You can schedule your first replacement when you prepare your furnace for the weather change that comes with fall and again halfway through the colder season.

How to Change Your Humidifier Water Panel

If you are wondering just how to change your humidifier water panel, there is no need to worry because the process usually takes a few minutes. (depending on the model you have).

No real technical or mechanical knowledge is needed, and the whole process is about as complex as changing the batteries in your remote. You just need to locate the unit and follow the steps below.

Step 1. Remove the cover- Most covers should come off easily with a button or pressure panel that releases them.

Step 2. Remove the old one- You should take out the enclosure that holds the humidifier water panel and swap the replacement unit in.

Step 3. Replace the enclosure- Once you have inserted the new unit, you should then replace the enclosure, ensuring to put it back in the same way you took it out.

Step 4. Ensure the unit is secure- You should secure whatever latch you used to release the enclosure and check to make sure it is stable.

Step 5. Replace the cover- Once you have verified that everything looks like it did before, you can replace the cover.

Need a visual?

How to replace your whole house humidifier water panel...

Simple instructions on how to replace the water panel on your whole house humidifier. Whether you own a humidifier manufactured by Aprilaire, Honeywell, Skuttle, or any other "flow through" unit - this video will help you keep your humidifier in new condition.

Important to note:

Before you start, turn off your heating and cooling system.

Each humidifier can have unique steps involved when changing your water panel. There are instructions that come with the water panel carton or manual. If experiencing any trouble it is always best to contact your HVAC professional.

Why You Need to Change Your Humidifier Water Panel

Not changing a humidifier water panel carries several different risks, both to you and to your climate control system. Since particles cake up and stay wet, it creates an ideal environment for mold and bacteria to flourish.

Think that might flare up your allergies?

Even more noticeable, though, is the reduced performance you're likely to get from your unit. Mineral deposits and particles from your water can build up within your panel. If it's clogged, it puts a greater strain on the fan motor, which can lead to your HVAC unit working harder. This will reduce its overall effectiveness. If your unit is integrated into your existing heating system, this can reduce the life of your fan.


At one point, we've probably all experienced the side effects before: 

  • Mold
  • Bacteria
  • Reduced Performance
  • Mechanical Failure

The good news:

It can be fixed.

By replacing your filter each heating season, you will maximize your humidifer performance. And failing to change it on a regular basis could cause leakage and more importantly lead to mold and bacteria.


Humidifier water panels often go unchanged. Maintenance is an important part of your system to keep it running efficiently. 

Replacing your water panel/filter on a timely basis will ensure you continue to add moisture to your home. In addition, you'll help to avoid the drain lines becoming clogged; which can lead to bacterial growth, and maintain your HVAC performance overall.

If you're suffering from any of the symptoms that are associated with the inability to acclimate to dry air, a dedicated humidifying system may be the best solution for you.

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