The CPAP machine treats obstructive sleep apnea by delivering a steady stream of pressurized air. This pressurized air creates an air splint to keep the upper airway open, preventing breathing pauses. When a CPAP machine fails, it disrupts therapy and raises concerns about health. Understanding common failures allows users to quickly diagnose and resolve issues, minimizing downtime and ensuring consistent treatment.
Machine Is Completely Dead
The most straightforward failure occurs when the machine exhibits no signs of life, with no lights or motor noise present. The first step involves checking the external electrical path to confirm the device is receiving power. Verify the power cord is securely plugged into the wall outlet and firmly seated where it connects to the back of the CPAP unit.
The wall outlet may be the source of the problem, so test it with a different small appliance, such as a phone charger, to confirm functionality. If the outlet is part of a series, a tripped circuit breaker could be interrupting the power supply. Also, ensure the main power switch on the machine, if present, is toggled into the “on” position, as accidental bumping can switch it off.
For individuals using a travel setup or external battery backup, failure might be due to a depleted battery or a poor connection at the DC power inlet. Some CPAP models require a specific power adapter or inverter for alternative power sources. Using the incorrect hardware can prevent the machine from powering on. Addressing these external power checks first is the quickest way to rule out basic electrical disconnection.
Low Pressure or Intermittent Air Flow
A more complex issue arises when the machine turns on but fails to deliver the required therapeutic pressure or the airflow is inconsistent. The most frequent cause of insufficient pressure is a significant air leak, often originating from the mask interface. Mask leaks occur when the seal is compromised due to improper sizing, incorrect strap tension, or the natural degradation of the silicone cushion over time.
Leaks reduce the net pressure reaching the airway, potentially dropping the effective pressure below the prescribed setting needed to prevent airway collapse. Users should inspect the entire length of the tubing for small holes, tears, or cracks, especially near the connection points. Even a pinhole can dramatically reduce the pressure delivered.
Another common restriction occurs at the air filter, which captures dust and particulate matter before the air enters the blower motor. If the disposable filter is visibly dark or clogged, it restricts the machine’s ability to draw in ambient air. This restriction forces the motor to work harder and may prevent it from reaching the required positive pressure level, resulting in low or struggling airflow.
Many modern CPAP devices incorporate a heated humidifier; the water tank must be seated perfectly flush within its chamber to operate correctly. If the tank is misaligned, a pressure sensor might interpret the configuration as a safety risk or a leak. This can cause the machine to either reduce the delivered pressure or halt the airflow entirely. Confirming the proper engagement of the humidifier tank’s seal is a simple, often overlooked troubleshooting step.
Some machines allow users or clinicians to adjust the pressure settings, and accidental alteration could cause the machine to deliver a lower pressure. Most devices require a specific code or access menu for changes. Verify the current pressure setting displayed on the screen matches the prescribed level to ensure correct therapy delivery. If the machine uses a pressure ramp feature, ensure the ramp time has completed, as pressure starts lower and gradually increases during this period.
Issues Related to Humidification and Noise
Problems not involving core pressure delivery, such as excessive noise or water issues, can still signal a malfunction impacting the user experience. A sudden increase in noise, such as humming, rattling, or squealing, often indicates mechanical stress within the device. This stress might stem from a degrading blower motor bearing or a loose internal component vibrating against the casing.
Sometimes noise is less serious and is simply caused by a loosely fitted filter cover or an improperly connected hose vibrating against a bedside table. A high-pitched, rhythmic squealing might also be acoustic feedback, similar to microphone feedback. This occurs when air leaks from the mask or tubing and immediately re-enters the machine’s intake. Addressing these simple external connection issues can often resolve minor noise complaints.
Issues related to humidification typically involve “rainout,” which is the accumulation of condensation inside the tubing and mask. Rainout occurs when the warm, humidified air cools rapidly as it travels through the ambient-temperature tubing, causing water vapor to condense into liquid droplets. This condensation can cause gurgling noises and may splash onto the user’s face, disrupting sleep.
Addressing rainout often involves using a heated tube, which maintains the air temperature to the mask, or adjusting the humidifier and heated tube temperature settings. Another issue is the buildup of mineral deposits, or scale, within the water tank, especially if tap water is used instead of distilled water. This mineral buildup can restrict the flow of humidified air or interfere with water level sensors.
Identifying Internal Malfunctions and Next Steps
When external checks and routine maintenance fail, the problem likely lies within the machine’s sealed internal components. These internal malfunctions often involve the blower motor, pressure sensors, or the main logic board controlling operations. A failure in one of these areas is usually indicated by a specific error code displayed on the screen, such as E-22 or Sensor Error.
These error codes are unique to the manufacturer and model, serving as a diagnostic shorthand indicating the precise failed component, such as an overheated motor or a faulty pressure transducer. Users should immediately document any error codes that appear, along with a detailed description of the machine’s behavior leading up to the failure. This documentation is invaluable for professional diagnosis.
Attempting to open the machine casing to inspect or repair internal components is strongly discouraged. This action voids the manufacturer’s warranty and can expose the user to electrical hazards. The next step is to contact the Durable Medical Equipment (DME) provider, who supplied the CPAP machine, or the manufacturer directly. The DME provider is typically the first point of contact for troubleshooting and warranty claims.
Before calling, users should locate the machine’s serial number and purchase date, as this information determines the remaining warranty coverage. Most CPAP machines come with a two-year warranty covering internal component failures and motor degradation. The provider uses the documented error code to determine if the machine requires repair, replacement, or a loaner unit to ensure therapy continuity while the device is serviced.