7 Reasons Why Your CPAP Is Losing Pressure – How To Fix It

A broken motor, loose seal, cracks in the mask and tube or a dirty filter can cause a CPAP machine to generate low-pressure or insufficient oxygen. Other causes include inadequate or infrequent maintenance of the CPAP machine, a defective compressor, or improper airflow.

More than 700,000 people globally rely on CPAP therapy to manage sleep apnea. Although a CPAP is highly effective in treating sleep and breathing issues, it can sometimes malfunction and start losing pressure.

In this article, we’ll discuss how to fix a CPAP machine that is losing pressure. First, we will step through each of the reasons for its malfunction, including the diagnosis for each problem, and its easy fix.

What Does It Mean When a CPAP Machine Is Losing Pressure?

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A CPAP machine loses pressure when the system fails to generate the set (or required) pressure.

A patient suffering from sleep apnea has respiratory problems that cause involuntary breathing to stop while sleeping. The CPAP therapy employs a system that pressurizes air and steadily supplies it to the patient, ensuring normal breathing.

CPAP machines allow the users to set a comfortable pressure. This generally ranges from 6 cmH2O to 14 cmH2O is considered appropriate; however, this varies depending on the severity of the condition.

While extremely high pressure can cause discomfort and dryness in the mouth, making it difficult to sleep, low pressure carries a risk of obstructive sleep apnea. Therefore, it is imperative to maintain the pressure within the optimal range suggested by your doctor.

Various factors like a loose mask, a worn-out machine, condensation issues, etc., can cause the machine to lose pressure.

If your CPAP is also blowing cold air, Plentiful Air has this complete troubleshooting guide available here.

How a CPAP Machine Works

Before discussing the potential reasons why your CPAP might be losing pressure, it’s important to know how a CPAP works.

A CPAP system typically has three components; a machine, mask, and tube.


The machine constitutes the following:

  • Motor: The motor draws air from the room into the system and pressurizes it by compression.
  • Air Filter: The air is passed through a filter to remove contaminants, making it safe to breathe.
  • Heater: CPAP devices send humidified air to the throat to prevent dryness. Since warm air tends to absorb and retain moisture, CPAP machines have a heater to heat the filtered air.
  • Water Tank: The warm air is passed over a water tank for humidification.


The patient inhales the hot and humid air through a mask. Depending on patients’ face contour, breathing pattern, and special medical conditions, CPAP masks are available in three different types:

  • Nasal Pillow Masks: They are lightweight and minimal in design, especially suitable for claustrophobic individuals. 
  • Nasal Masks: They provide a higher pressure than the nasal pillow masks. However, they are not designed for mouth breathers.
  • Full Face Masks: They provide the highest pressure among the three and are suitable for the mouth and nose breathing.


The tube connects the mask with the oxygenation device (CPAP machine). Some tubes also have heaters to prevent condensation as the humidified air passes through.

Reasons Why Your CPAP Machine Has Lost Pressure

Following are the reasons why your CPAP machine might be generating lower than the set oxygen pressure:

1. Saturated Filter

Low pressure from the CPAP machine is most commonly caused from a clogged filter.

Patients with sleep apnea often have compromised respiratory and immune systems. The filter placed in the CPAP machine traps the majority of the contaminants like dust, debris, and germs, ensuring a continuous supply of clean and safe-to-breathe air.

Apart from this, the filter also keeps any contaminants from collecting in other components; making it essential to keep the machine running.

Generally, inadequate maintenance of the machine (or infrequent cleaning) causes the filter to become saturated. The filter then fails to trap further pollutants. Accumulating dust and other particles in the system increases the resistance, sending the machine into overdrive. This leads to overheating, which may even damage or break down the CPAP machine.

Apart from the machine, the debris build-up also results in the degradation of the mask and tube.


Regularly cleaning and maintaining the filter is the key to preventing any complications with the machine. Ideally, you should clean the filter at least once a week. Here’s how you can clean the filter:

  • Turn the machine off and take the filter out
  • Rinse the filter with warm water
  • Wash it with mild soap
  • Let it dry before placing it back

Note that some CPAP machines come with disposable filters, which cannot be washed and should only be replaced regularly.

Generally, you need to replace the filter every four weeks (or sooner if swelling of the filter pores is visible).

2. Defective Motor

CPAP machines have a motor that pulls air into the system. This air is pressurized to facilitate its delivery through the tube, as well as to ensure comfortable inhalation. Efficient airflow is therefore imperative for the optimal functioning of a CPAP machine.

The CPAP motor sometimes breaks down due to electrical problems or internal defective components, thus failing to draw in air. Due to insufficient air supply, the oxygen pressure is also low.

If your machine refuses to turn on, produces rattling sounds when running, or automatically turns off a few minutes into the operation, it indicates a defective motor.


A professional technician can fix the motor. However, the tune-up is expensive and ineffective since there’s a high chance of the motor malfunctioning again. Therefore, if this is clearly your problem we recommend investing in a new CPAP machine instead of getting the motor repaired, especially if yours is more than five years old.

3. Cracks in the Tube

Cracks in CPAP tubes can cause the air to leak out, causing the machine to lose pressure. Air leaking from the tube generally makes a specific wheezing noise with which you can identify the cracks.

Apart from cutting down the oxygen pressure, cracks in the mask allow the air to reach your eye, which may lead to itching and redness. It can also cause your skin to dry out. Therefore, fixing this problem immediately is crucial.


The only solution to a broken/cracked tube is replacing it. Typically, a CPAP machine’s tube lasts for around three months. It is essential to note that CPAP tubes come in various types; the primary ones of which are as follows:

  • Heated CPAP Tubes: These tubes keep the hot, humid air from cooling down and condensing. They help keep the air warm and moist, making breathing comfortable. This is suitable for people who use the humidifier along with the CPAP machine.
  • Standard CPAP Tubes: They measure 22mm and are used with machines that do not come with a humidifier.
  • Slim CPAP Tubes: They are 15mm in diameter and are preferred for being lightweight.

When connecting a new tube, ensure it is suitable for your condition and compatible with your CPAP system.

4. Loose Mask

Your CPAP mask must be tightly secured to deliver a steady pressure. Loose seals allow the air to escape from the system and thus, reduce the pressure.


Here’s how you can tighten the mask seal to resolve the problem:

  1. First, wear the mask when sitting.
  2. Then, turn on the CPAP machine.
  3. Lay down and use the mask straps to fix the mask in position and secure the seal.
  4. Pull the mask away from the face to inflate the lower side for a few seconds.
  5. Pull the mask up and observe if it is still leaking air.

If tightening the seal does not work, you probably need to buy a smaller-sized mask. However, if your mask is making excessive noise, Plentiful Air has detailed information on noisy CPAP masks available here.

5. Cracks in the Mask

Cracks in the mask (often due to excessive accumulation of dust and oil) can also cause the machine to lose pressure. Since humidified air passes through the mask, vapors collected on the wall of the mask are a common sign of cracks.


A broken mask cannot be fixed and requires replacement. Adequately cleaning the machine to prevent degradation is essential to make the mask last long. Wiping the mask with mild soap and water or sanitizing it daily helps.

6. Broken Compressor

CPAP machines have a compressor that pressurizes the incoming air before sending it for humidification. A broken compressor renders the machine incapable of generating and delivering pressurized oxygen to the user.

The following signs indicate a defective compressor:

  • The machine makes growling sounds during operation.
  • The CPAP machine abruptly turns off.
  • Your CPAP machine generates irregular pressure.


Get an experienced technician to test and repair the compressor. However, if your compressor breaks down frequently, replacing it with a new one is more cost-effective.

7. Old Machine

CPAP machines have a lifespan of three to five years. After this period, the device starts wearing out and needs replacement. Following are the signs that indicate your CPAP machine needs replacement:

  • The machine produces noise during inhalation.
  • You notice that the humidifier water is not consumed.
  • The device requires frequent tune-up.
  • You face difficulty breathing even when the machine is on.


When the machine starts malfunctioning frequently, it needs to be replaced. Since CPAP machines from different brands have varying designs and working mechanisms, it is always better to go for the same brand if it works well for you. You can check with your medical insurance company if they provide coverage for the machine.

What Happens If my CPAP Pressure is Too Low?

Low CPAP pressure renders the therapy ineffective in treating sleep apnea. The patient might also experience shortness of breath and aerophagia (gasping for air during the night). This results in secondary complications like bloating, dryness, gas, discomfort, irritability, and fatigue.

Can I Increase the Pressure on my CPAP?

CPAP machines allow the users to set comfortable air pressure, this includes the capacity to increase the pressure when desired. Some devices also have an auto-mode that adjusts the pressure by sensing the resistance in breathing.

All CPAP machines vary in design and operate differently. You can refer to your device’s user manual to learn how to increase the pressure on your CPAP. Since there are complications associated with high CPAP air pressure, it is better to consult a doctor to know the suitable pressure settings for yourself.

How Do I Know If My CPAP Pressure Needs Adjusting?

The pressure on a CPAP machine should be adjusted when signs of low pressure (dryness, dyspnea, perspiration, bloating, and irritation in the skin, higher than average AHI) or of high-pressure leaks through the mask and mouth breathing) are observed.

Improper CPAP pressure, be it too high or low, has manifestations and causes discomfort during sleep. Following are the signs you can look for to know if your CPAP pressure needs to be increased:

  • The mouth and nose are dry
  • Irritation and redness in eyes
  • Snoring during sleep
  • Difficulty breathing
  • Wake up with shortness of breath
  • Excessive perspiration
  • You need to swallow air
  • Bloating after using the machine
  • Fluid leaks from the ear
  • Fatigue and tiredness during the day

One of the definitive ways to find out if you should adjust your CPAP pressure is by AHI. The apnea-hypopnea index or AHI is a scale to gauge the severity of sleep disorder (apnea).

You can calculate it by dividing the total number of apneic (when breathing pauses during sleep) and hypopnea events (shallow breathing) and multiplying the result by the number of sleeping hours.

A score of fewer than five events per hour is considered normal. If your AHI is higher than the average, you should consider increasing your CPAP pressure.

If you are concerned your CPAP machine is not recording data properly, Plentiful Air has more information available here that can help you fix it.

On the other hand, the following signs indicate a high CPAP pressure:

  • Dryness in mouth and nose, even with humidification
  • Breathing through mouth
  • Leaks through the mask

Why Is My CPAP Not Blowing Enough Air?

Insufficient pressure from the compressor leads to a decreased outflow of air from the CPAP machines. A broken compressor, inadequate airflow, broken masks, large-sized masks, and inefficient humidification are some other potential causes of a CPAP not blowing enough air.

Discomfort, difficulty breathing, excessive sweating, and snoring are all signs that your CPAP machine is not blowing enough air. Adjusting the pressure and fixing the root cause of leaking air is essential to resolve the issue.

Theresa Orr

Theresa Orr holds a PhD in Earth Science and specializes in determining past climates from rocks using geochemistry. Her passion for clean water, soil and air drives her to provide easy to understand information for everyone to read.

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