Is my ResMed CPAP humidifier working correctly?

We receive CPAP and BiPAP machines with this issue almost every day. I’d like to hopefully save you some time and money by helping you figure out if your CPAP climate control system is working properly and teach you how to adjust the settings yourself. If all else fails, you can send it into us to evaluate. We do provide free repair estimates. But the goal is to have you use your CPAP comfortably with just a few adjustments to the comfort setting. Below are some frequently asked questions and how to address them.

ResMed AirSens 10

Why is there water on my face or in my mask when I wake up?

Rain-out is caused by the air cooling too quickly and condensing in your mask or on your face or having your humidifier heat setting too high. If you aren’t already using a heated hose, getting one will greatly reduce the chance of rain-out. The ResMed Air10 Series has an automatic climate control setting that was created to prevent rain-out. To check if your device is using the automatic climate control setting, go into your options menu. If the climate control is set to manual, go to that setting, push the knob in, turn it to auto and push the knob in again. This will only appear if you are using a heated hose and it is plugged into the device. 

Sometimes the Air10 auto climate control does not prevent rain-out. In this case, change the climate control to manual following the steps listed above. Then lower your heat setting (if you’re not sure where to start, change it to 4). You may also change the climate line (heated hose) temperature. You can start with 81F. ResMed has a video showing this process, which you can find by clicking here.

ResMed S9 AutoSet

For ResMed S9 users, find the water drop icon when turning the dial. Select it by pushing the dial in. Turn the dial again to your desired humidity setting. Start with a setting of 3 if you aren’t sure where to start. Push the dial in to make your selection. To change the tube temperature, find the thermometer icon and select it. Turn the dial to your chosen temperature and push in the dial to select it. If you’re not sure what temperature to start with, try 80F. Click here to see a video on how to make these adjustments to your S9.

My humidifier doesn’t seem to lose any water at night. Is it working?

When the environment is more humid, the heater will not need to turn on as often to reach the auto climate control setting or your manual setting for humidity. If you do not feel dry at night, then the humidifier is only turning on to heat the water just enough to make you feel comfortable. Therefore, less water will be used, and this is normal. As long as you feel comfortable, there’s no need to worry. But if you are feeling dry, try turning up the heater. There may be less humidity in the air, so you need a higher humidifier setting.

There are checks you can do on your own to test the humidifier function. On the Air10 models, it’s easiest to check your sleep reports. Look for a green smiley face. This indicates that your humidifier is working properly. If it produces a red sad face, send your unit in for repair; the humidifier is not working as it should. Send in your climate line hose, as well, so we can verify it is working properly. These hoses can wear out over time, especially if they are being connected and disconnected repeatedly.

You can manually check if your heater is working by running the warm-up. Go into your options and select Warm up. Hover your hand over the heater plate to feel if it is warming. Do not touch the heater plate, as it could burn your skin. 

My humidifier is working, but I still feel dry. What should I do?

If you have your humidifier and hose setting all the way up and still feel dry, there could be other issues causing your dryness. Some medications can cause dryness; talk to your doctor about items like Biotene spray to help with your dryness or possible medication alternatives. 

Your mask could be leaking, so you’re not getting enough humidity. One sign of a mask leak could be that the humidifier is going through all the water in the chamber in one night when filled to the full line. Talk to your respiratory therapist or sleep doctor about possibly fitting a new mask size or type to your face. If you have lost weight, you may need a smaller mask size to prevent leaks. Your sleep position might also cause it to leak. Perhaps a different mask type will work better with your sleep position. 

If all else fails, and you aren’t sure what is going on with your humidifier, you can send it in with your CPAP and have us evaluate its function. We provide a prepaid shipping label to send your unit to us by clicking on the Schedule Service Now button on our website. We will evaluate your unit and let you know what is wrong with it before doing any repairs. This evaluation is free. Once we get your approval and payment for repairs, we’ll repair your unit and send it back to you. If you decide not to go through with the estimated repairs, we can send it back to you for just the cost of return shipping, or throw it away for you and you owe us nothing. 

We are happy to serve you. Let us know what we can do for you.

Laurie DeChello, MPH, CPH is the health educator and a co-owner of Altra Service Professionals, Inc. Laurie writes a health blog for the ASP website regarding issues related to respiratory illnesses and treatment. She is a certified technician repairing ventilators and sleep apnea equipment. She also assists in keeping the office running smoothly. Laurie previously taught courses in the health sciences with Kaplan University. She also taught public health courses at the University of Connecticut and performed epidemiologic research (the spread and control of diseases) also at the University of Connecticut for 11 years. She is widely published in the medical literature. Laurie lives in Florida with her amazing husband, two adorable boys and numerous animals on their small farm. She enjoys cooking and entertaining at her home. Laurie has her Master’s in Public Health and is also Certified in Public Health. If you have a public health question or would like more information about your illness, please contact her at LaurieD@altraservice.com. She is also available to develop and lead health seminars.