Signs Your CPAP Machine Is Not Working or Needs Adjusting

Continuous positive airway pressure (CPAP) is widely regarded as the best treatment available for obstructive sleep apnea, a breathing disorder that affects millions of people. This treatment is highly effective when properly used and the CPAP machine is kept in good working condition.

There are ways to know if your CPAP device has become less effective because it's not working properly, such as persistent symptoms, snoring, and cold air from the humidifier. Your device may need to be adjusted or replaced entirely.

This article explains some of the reasons why a CPAP machine is no longer providing you with the best results. In addition, it offers tips that may fix the problem in many cases.

Woman lying in bed using a CPAP machine
Juanmonino / Getty Images

1. You're Breathing In Cold Air

Cold air coming in through the CPAP machine can be a sign that the humidifier isn't working properly. Humidity in the CPAP air is extremely important because it helps prevent dry mouth, difficulty sleeping, and other uncomfortable side effects.

The two main problems that could be happening with the humidifier have to do with the water chamber and the hot plate:

  • Your heated humidifier tank should be refilled about once every two to three days. If that's not the case, the temperature and humidity settings may need to be adjusted. But if the water never goes down, the humidifier may not be working at all.
  • The hot plate under the water chamber may not be warming up. There is still some evaporation as the air passes over the water but it's at a much slower rate. This may mean that the heating element isn’t working.

The humidifier should be fairly quiet when it's operating. If it is pretty noisy when it's running, see if you need to get the humidifier replaced. Start by checking the humidity settings on your machine and contact a CPAP specialist for additional help.

2. You're Still Snoring or Having Apnea

Snoring should never occur when the CPAP pressure is set properly. That's because the constant flow of air will keep the airway open and prevent its collapse. It also stops the airway tissue vibrations that cause snoring.

If you are snoring with your CPAP mask on, and the mask is not leaking, talk to your healthcare provider. The pressure likely needs to be increased to be fully effective.

You may have pauses in your breathing or episodes where you wake up gasping and choking even while using your CPAP machine. If these events are confirmed, it's likely the pressure setting needs to change.

The apnea-hypopnea index (AHI) counts the number of breathing disruptions that occur per hour of sleep. You can sometimes find an AHI display on your machine or monitoring apps. If it is greater than 5 when you wake up, then the pressure should be increased.

If you have any of these problems, you should discuss them with your sleep specialist.

3. You Feel Worse

Some people who start using a CPAP machine will see benefits in a matter of days or weeks. Signs that CPAP treatment is working may include:

  • Fewer awakenings 
  • More refreshing sleep
  • Decreased daytime sleepiness
  • Better concentration
  • Improved short-term memory or mood

Over the long term, other conditions associated with untreated sleep apnea may also improve. These may include high blood pressure, heart failure, or diabetes.

Symptoms of sleep apnea are usually what lead to CPAP use. If the same symptoms return, this may mean the machine is not delivering the best possible results. You should talk this issue over with your healthcare provider.

When there is a problem, people using CPAP will most often complain that their excessive daytime sleepiness has returned and again need to have long or frequent naps. Possible causes include a mask leak or not enough treatment pressure.

Other changes in your health or lifestyle may cause your symptoms to return. That may mean your CPAP settings need to be adjusted. You may need to check the CPAP settings if any of the following things apply:

  • Weight gain
  • Alcohol use near bedtime
  • Advancing age

4. Your CPAP Machine Is Aging

Unfortunately, CPAP machines do not last forever. Your machine may start to make a funny noise, become harder to operate, or won't generate the same pressure as before. That may mean it's time to replace the machine.

How long does a CPAP machine last?

In general, your CPAP machine should last about five years. Most insurance companies will pay to replace the CPAP machine after that time.

These devices do have some degree of built-in obsolescence, meaning that they are not meant to work forever. They will gradually begin to fail and you'll need to replace it with a new device.

If your CPAP machine is old enough and it's no longer working well, a replacement is due. Fortunately, next-generation models often have improved features. The new machines often are quieter and easier to use when compared to old equipment.

5. The CPAP Machine Just Isn't Working

If the machine simply does not turn on, it clearly is not working properly. When plugged in, most CPAP machines can be turned on with the push of a button. If you place it on a specific setting, some machines will even start working automatically when you breathe into your connected mask a few times.

If the CPAP stays off or there is no airflow at all, you should take it to your equipment provider. They can determine if the device needs to be repaired or replaced. This is often the case when it has stopped working after it is dropped.

There can be other signs that something is amiss with your CPAP machine. That's because there are water and heating systems that can malfunction, too, apart from the power supply. Here are a few to consider.

  • If the air feels uncomfortably cool, this is further evidence that the machine is not working.
  • Water may condense inside heated tubing in some machines that have them. This tends to mean the humidity setting is too high, the tubing is not connected right, or it's just not working properly.
  • The machine may also be more noisy and it seems to provide less airflow than it did before.

How to Replace a Broken CPAP

When you've done all the troubleshooting you can and your machine still isn't working, it may be time for a replacement. Here's what you can do to get a new CPAP machine:

  • Check the warranty period: Most CPAP machine manufacturers offer a two-year warranty period. If you have any problems with your machine during this period, you can contact the manufacturer about a replacement. Contact information for the manufacturer can be found in the user's manual or on the manufacturer's website. If your product is out of warranty, it is probably time to replace it anyway.
  • Get a new prescription if you need to: Check your prescription when you're replacing your machine. You want to make sure the new machine meets the right air pressure requirements for your needs. When you're ready to replace the machine, it doesn't hurt to check in with your healthcare provider to see if you need any changes to your prescription.
  • Check with your health insurance company: Talk to your insurance company or check your policy to see if durable medical equipment like a CPAP machine is covered. This may save you some money on a new CPAP machine, even if the machine is only partially covered by your health insurance.

Summary

Your CPAP machine is only as good as the health benefits it provides. When it's working well, you'll feel far more rested and your symptoms of sleep apnea and snoring will be resolved.

But when the device isn't working properly, your symptoms may return. There are several reasons for why the CPAP machine may be failing. The problem can be with the power, tubing, or humidifier. Or it may just be that an old machine needs to be replaced.

In other cases, changes in your health or lifestyle may simply mean that your settings need to be changed to ensure you're getting the right amount of pressure. If you believe that your CPAP machine is not working properly, call your equipment provider or sleep specialist and get your treatment back on track. Your sleep specialist can also help you find out the cause and offer solutions if apnea symptoms return.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cao MT, Sternbach JM, Guilleminault C. Continuous positive airway pressure therapy in obstuctive sleep apnea: benefits and alternatives. Expert Rev Respir Med. 2017;11(4):259-272. doi:10.1080/17476348.2017.1305893

  2. Konecny T, Kara T, Somers VK. Obstructive sleep apnea and hypertension: an update. Hypertension. 2014;63(2):203-9.

Brandon Peters, M.D.

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.