Empty and rinse the chamber daily

The humidifier chamber collects mineral deposits and bacteria if water sits in it overnight. Empty any remaining water each morning, then rinse the chamber under warm tap water. Use your fingers or a soft brush to wipe the interior walls where mineral buildup appears as white or tan residue.

Do not use hot water — it can warp the plastic. Tap water is fine for rinsing; you do not need distilled water for this step. Shake out excess water and set the chamber upside down on a clean towel to air dry while you prepare the rest of your equipment.

Key Takeaways

  • Empty and rinse the chamber every morning to prevent mineral deposits and bacterial growth.
  • Soak the chamber in equal parts white vinegar and distilled water for 30 minutes once a week to dissolve mineral buildup.
  • Use distilled water in the chamber itself, not tap water, to reduce the mineral deposits that require cleaning.
  • Replace the chamber every six months to one year, depending on your water hardness and how often you use your machine.
  • Never soak the heating plate or electrical connections — clean only the plastic chamber and lid.

Weekly deep clean with vinegar

Once a week, soak the chamber in a solution of equal parts white vinegar and distilled water. Fill a bowl or cup with the mixture and submerge the chamber for 30 minutes. The vinegar dissolves mineral deposits that daily rinsing cannot remove.

After soaking, scrub the interior with a soft brush or cloth, paying attention to corners and the bottom where deposits collect. Rinse thoroughly under running distilled water until the vinegar smell is gone. Air dry completely before refilling with distilled water for your next session.

Why distilled water matters for the chamber

Tap water contains minerals — calcium, magnesium, and others — that build up inside the chamber and heating plate. These deposits narrow the opening where water vapor enters the hose, reduce heating efficiency, and create a surface where bacteria can grow. Distilled water has these minerals removed, so it leaves no residue.

The cost difference is small: a gallon of distilled water costs one to three dollars and lasts several days of nightly use. Buying distilled water is cheaper than replacing a chamber every few months or dealing with mold in your tubing. Fill the chamber with distilled water only, not tap water.

Cleaning the heating plate without damaging it

The heating plate sits at the bottom of the chamber and should never be soaked or scrubbed. If mineral deposits form on the plate itself, dampen a soft cloth with distilled water and gently wipe the surface. Do not use vinegar directly on the plate — the electrical connections are nearby.

If the plate has heavy white buildup that will not wipe away, the chamber may be due for replacement. Attempting to scrape or soak the plate risks damaging the heating element and making the humidifier unsafe. Most manufacturers recommend replacing the chamber every six months to one year for this reason.

Signs the chamber needs replacement

Replace the chamber if you see discoloration that does not rinse away, cracks in the plastic, or a cloudy appearance inside even after vinegar soaking. If the heating plate no longer warms the water or heats unevenly, the chamber should be replaced as a unit. Do not attempt to repair the heating element yourself.

How often you replace the chamber depends on your water hardness. If you live in a hard water area (high mineral content), you may need a new chamber every six months. In soft water areas, a chamber may last a year or longer. Check your machine's manual for the manufacturer's recommendation for your region.

Storage and drying between uses

After cleaning, make sure the chamber is completely dry before storing it or refilling it. Moisture left inside creates an environment for mold and mildew to grow. Stand the chamber upside down on a clean cloth in a well-ventilated area for at least two hours, or overnight if possible.

Store the clean, dry chamber in a cool, dry place away from direct sunlight. Do not store it in a sealed container or plastic bag while damp. If you travel and need to pack the humidifier, may support the chamber is fully dry before sealing it in your CPAP travel case.

What not to do when cleaning

Never use bleach, hydrogen peroxide, or harsh chemicals on the chamber. These can damage the plastic, leave toxic residue, and harm your lungs when you inhale the vapor. Stick to white vinegar and distilled water — both are safe and effective.

Do not put the chamber in the dishwasher, even on a gentle cycle. The heat and detergent can warp the plastic and damage the heating plate. Hand washing is the only safe method. Never soak the entire humidifier unit or the machine itself — only the removable chamber gets wet.

Frequently Asked Questions

Can I use tap water if I clean the chamber more often?

No. Tap water will still leave mineral deposits even with daily cleaning. The minerals accumulate faster than you can rinse them away, and they can damage the heating plate over time. Distilled water prevents the buildup from starting, which is more effective than trying to clean it out constantly.

How do I know if my water is hard?

Hard water leaves white, chalky deposits on faucets and in kettles. If you see buildup on your bathroom fixtures, your water is likely hard. You can also buy an inexpensive water hardness test strip at a hardware store. Hard water areas may need chamber replacement every four to six months instead of yearly.

What if the chamber smells bad even after cleaning?

Soak it in vinegar solution for a full hour instead of 30 minutes, then rinse very thoroughly. If the smell persists, the chamber may have mold inside that cannot be fully removed. Replace the chamber and make sure you are emptying it daily and air-drying it completely between uses going forward.

Can I clean the humidifier chamber with a dishwasher tablet or denture cleaner?

No. These products contain chemicals not meant for respiratory equipment. Stick to white vinegar and distilled water only. These are the safest and most effective cleaners for CPAP equipment, and they cost very little.

Do I need to replace the chamber if I only use my CPAP a few nights a week?

Yes, follow the same replacement schedule as nightly users. Even occasional use leaves mineral deposits and creates conditions for bacterial growth. Replace the chamber every six months to one year depending on your water hardness, regardless of how many nights per week you use the machine.