Can You Use Tap Water in a Humidifier?

As indoor air quality experts, we’re frequently asked: can you use tap water in a humidifier? The answer is yes – but you might not necessarily want to. Tap water can cause unnecessary wear and tear on your humidifier and potentially spread unwanted bacteria throughout your home. Keep reading to learn about what type of water we recommend using in your humidifier.

Why Invest in a Humidifier

Humidifiers are excellent additions to most homes. They make our living spaces more comfortable by adding moisture to the air. Dry air can be harsh on the lungs of those with allergies and asthma. That’s especially true during the winter months. Humid air naturally feels warmer, too. You may be able to turn down the thermostat a few degrees and not notice a big difference in comfort. This inevitably leads to more affordable heating costs. Of course, the success of the device often lies with what water to use in the humidifier.

If you decide to add a humidifier to your home, be sure to learn how to clean it properly. Mold can grow quickly in these devices, which is why they should be thoroughly cleaned at least every other day. While this extra chore may sound annoying, you’ll be glad you invested a little time in maintaining your humidifier. When cleaned regularly, humidifiers can have a lifespan of several years.

What Type of Water Should be Used in a Humidifier?

So, can you use tap water in a humidifier? While you technically can; it’s not recommended. Instead, look for demineralized, distilled, and purified water at the store. This kind of water is less likely to result in mold and bacteria growth inside your humidifier. You’ll have less mess to clean up when maintaining your humidifier, and you won’t risk sending mold spores airborne. This means there’s a much lower risk of developing lung infections, too. All in all, it’s best to avoid tap water so you can sidestep these potential issues.

Can I Use Bottled Water in a Humidifier?

Bottled water is truly the best water to use in a humidifier. Not all bottled water is ideal, though. While bottled water is filtered, some minerals inevitably remain. This can present many of the same issues caused by tap water. Look for bottled water that has been distilled. This is the best way to ensure that no mold or bacteria will grow inside your humidifier.

What About Boiled Tap Water?

Boiled tap water is much better than tap water in a humidifier. Boiling can remove bacteria from the water, but it doesn’t remove the minerals. Actually, boiling water increases the mineral content. As steam evaporates, the mineral concentration rises. While distilled water is made from boiling water, distilled and boiling water are two different things. Distilled water is made by collecting the steam vapor from boiled water. Boiled water is simply heated and collected.

Using boiling water is better than tap water since it will have a lower chance of mold formation. Boiling water neutralizes mold spores, so you’ll have fewer issues cleaning and maintaining your humidifier. If you opt to use boiled water in your humidifier, make sure to let it cool before using it. Putting boiling water in a humidifier can damage it. Instead, allow boiling water to come to room temperature before adding it to your humidifier.

Breathe Easy with Indoor Air Quality Solutions from Aire Serv^®

For better or for worse, humidifiers can really impact indoor air quality . Knowing what water to use in a humidifier can make all the difference. Tap water ups the odds of mold growth and lung infections, while distilled water makes your home feel warmer and more comfortable. The difference is obvious. The next time you need to refill your humidifier, be sure, you’re doing so with distilled water.

Need help with a whole-home humidifier? Or perhaps you want additional solutions to improve your home’s indoor air quality. The experts at your local Aire Serv can provide insight and options for doing so. Call us or request an appointment today.

This article is intended for general informational purposes only and may not be applicable to every situation. You are responsible for determining the proper course of action for your home and property. Aire Serv is not responsible for any damages that occur as a result of this blog content or your actions. For the most accurate guidance, contact the Aire Serv location nearest you for a comprehensive, on-site assessment.

FAQs About the Best Water for a Humidifier

As an industry leader and a brand that is trusted by homeowners and businesses nationwide for our knowledge and experience, we’re happy to answer your HVAC questions. Here are answers to some of the frequently asked questions about the best water for a humidifier.

Should you use distilled water in a humidifier?

Use distilled water in a humidifier whenever possible. This will help your humidifier operate more efficiently and consistently.

Tap water and even some bottled or spring waters contain minerals that can leave behind white dust or hard scaling as the water evaporates, which can clog humidifiers. Distilled water has had minerals removed, preventing this buildup.

Distilled water also helps reduce mold and bacterial growth. The minerals and impurities found in tap water can create a breeding ground for mold and bacteria inside the humidifier. Since distilled water is purified, it's less likely to harbor these microorganisms.

What kind of water should you use in a humidifier?

While distilled water is the best water to use in a humidifier, there are other options:

• Reverse osmosis (RO) water: Water filtered through a reverse osmosis system removes a significant amount of minerals and impurities.
• Demineralized water: Similar to distilled water, demineralized water has had its minerals removed and is suitable for humidifiers.
• Purified water: Purified water has had many impurities removed, which helps reduce mineral buildup. It’s a workable alternative to distilled water for maintaining a cleaner humidifier and indoor air quality.

Do you have to use distilled water in a humidifier? Not necessarily, but distilled water is the best way to keep your humidifier clean and efficient and contribute to a healthier indoor environment.

Can you use regular water in a humidifier?

Using tap water in a humidifier is generally not recommended due to the minerals it contains. These minerals can lead to a fine white dust settling on your furniture and can also build up inside the humidifier, causing scale and reducing its efficiency. This buildup can eventually damage the unit and shorten its lifespan.

Tap water can also harbor bacteria and mold. When the humidifier runs, these microorganisms can be aerosolized and released into the air you breathe, potentially causing health issues.

While convenient, using tap water requires more frequent cleaning of your humidifier to remove mineral deposits. Some manufacturers may even state that using tap water can void the warranty. If you must use tap water, check the manufacturer's recommendations for your specific humidifier. Distilled or purified water is a much better choice for maintaining both the humidifier's performance and your indoor air quality.

How to make tap water safe for a humidifier?

While distilled or purified water is generally recommended for humidifiers, you can take steps to make tap water safer to use. Here's a step-by-step process for using tap water in a humidifier:

Method 1: Boiling Water for Humidifier

Using boiled water in a humidifier will help kill many microorganisms, but it will not remove the minerals present in tap water. In fact, as some water evaporates during boiling, the mineral concentration might slightly increase. Therefore, you may still experience some mineral buildup in your humidifier, which will require more frequent cleaning.

1. Boil the water: Pour tap water into a clean pot. Bring it to a rolling boil on your stovetop.
2. Boiling time: If you live at an elevation of 6,500 feet or less, boil the water for at least one minute. If you live at a higher elevation, boil the water for three minutes to ensure the most harmful bacteria and viruses are killed.
3. Cool completely: Allow the boiled water to cool down completely to room temperature before adding it to your humidifier. Adding hot water can damage the unit.
4. Use promptly: Use the boiled water within 24 hours to minimize the risk of recontamination.

Method 2: Water Filter Pitcher

While a water filter pitcher can improve the quality of tap water by removing chlorine and some other impurities, its ability to remove hard water minerals (calcium, magnesium) that cause scaling is limited. Simply fill a water filter pitcher with tap water and allow the water to filter through the system before adding it to the humidifier.

Method 3: Reverse Osmosis (RO) System

RO systems are very effective at removing minerals, making the water much better for humidifier use and reducing white dust. However, they require a more significant upfront cost, including professional plumbing work and regular filter replacements.

Can tap water cause mold in my humidifier?

Yes, tap water can contribute to mold growth in your humidifier. Tap water contains minerals and impurities that can serve as nutrients for mold and bacteria. When the humidifier runs, the warm, moist environment inside the tank and other components creates ideal breeding conditions. These contaminants can then become aerosolized and dispersed into your home's air.

Regular cleaning is always important to prevent mold in humidifiers, but using tap water makes it more likely for mold to establish itself. Switching to distilled or purified water, which lacks these nutrients, significantly reduces the risk of mold growth within your humidifier.

Can I clean my humidifier with tap water?

While you can technically clean your humidifier with tap water, it's not the best practice for thorough cleaning or preventing future issues. Tap water contains minerals that can contribute to scale buildup inside the humidifier, even during cleaning. This buildup can hinder the effectiveness of the cleaning process and make future cleaning more difficult.

For optimal cleaning, use white vinegar, diluted bleach solutions (following manufacturer instructions carefully), or specialized humidifier cleaning solutions. After cleaning with these agents, rinse all parts thoroughly with distilled or purified water to remove any residue and prevent the reintroduction of minerals. Using tap water for the final rinse can leave mineral deposits behind.

Will my allergies worsen if I clean my humidifier with tap water?

Cleaning your humidifier with tap water could potentially worsen your allergies, though indirectly. Tap water contains minerals that can leave behind residue even after cleaning. This mineral buildup can create a rough surface that's more hospitable to mold and bacterial growth. If these allergens then get dispersed into the air when the humidifier runs, it could exacerbate your allergy symptoms.

If you don't rinse thoroughly after cleaning with tap water, any remaining cleaning solution mixed with tap water residue could also become aerosolized, potentially irritating your respiratory system and triggering allergy-like reactions. Using distilled or purified water for rinsing after cleaning is a better practice to minimize these risks.

If allergies persist, consider air purification systems to help manage symptoms.

What type of water should I use in an ultrasonic humidifier?

Distilled water is highly recommended for ultrasonic humidifiers. Ultrasonic technology doesn't boil the water, so any minerals or impurities in tap or even filtered water can be aerosolized and dispersed as a fine white dust, potentially harming air quality and irritating respiratory systems. Distilled water minimizes this risk and helps keep the humidifier cleaner.

When do I need professional humidifier repair or replacement?

You'll likely need professional humidifier repair or replacement when you observe the following:

• Significantly reduced humidity: If your hygrometer consistently reads low, even when the humidifier is running, it indicates a major malfunction.
• Water leaks: Any noticeable leaks around the unit suggest internal damage that could worsen and cause further issues.
• Strange noises: Loud or unusual sounds like grinding, rattling, or buzzing that aren't normal operational noises.
• Foul odors: Persistent bad smells emanating from the humidifier even after cleaning, possibly indicating mold or bacterial growth within inaccessible parts.
• Electrical issues: If the unit won't power on or frequently trips your circuit breaker, it points to a serious electrical problem.
• Visible damage: Cracks in the water tank or other structural damage that affects performance or safety.
• Age of the unit: If your humidifier is nearing or has exceeded its typical lifespan (often 5 to 10 years for portable units and 10 to 15 years for whole-house units), replacement may be more cost-effective than repairs.
• Costly repairs: If the estimated repair cost approaches or exceeds half the price of a new unit, replacement is usually the better long-term investment.

Humidifiers usually require professional service. Contact an HVAC professional for humidifier services in your home or commercial humidifier repair.