A Continuous Positive Airway Pressure (CPAP) machine uses air pressure to keep your airway open while you sleep, treating obstructive sleep apnea. When the device fails to power on, it disrupts therapy and requires immediate attention. The cause is often a simple issue with connections or assembly, not a major internal defect. This structured approach helps diagnose the problem by starting with basic external checks.
Verify the Power Source
Begin troubleshooting by checking the electrical outlet, as this is the simplest and most common point of failure. Confirm the wall outlet is providing power by plugging a different small appliance, such as a lamp, into the same socket. If the other device does not turn on, the problem is with your home’s electricity, not the CPAP unit.
Also check your home’s circuit breaker box to confirm the circuit has not been tripped by an overload. If the outlet is controlled by a wall switch, ensure the switch is in the “on” position. Finally, trace the main power cord from the wall outlet to the power adapter. Check the cord for any signs of physical damage, such as pinches or cuts in the insulation.
Inspect the Machine’s Power Supply
After verifying the wall outlet is functional, examine the CPAP’s power supply components, often called the power brick or transformer. This external adapter converts alternating current (AC) into the direct current (DC) needed by the machine’s electronics. Many modern CPAP power bricks feature an indicator light, typically green, which confirms the brick is receiving power and functioning correctly.
Ensure the cord connecting the power brick to the CPAP unit is fully inserted into the machine’s power port. These proprietary connections are designed to fit snugly, and a loose insertion prevents the machine from receiving power. If using a battery backup or auxiliary DC power source, confirm it is fully charged and the connection cable is compatible with your model. A failure at any point in the power chain will result in a complete power failure.
Check for Assembly Errors
CPAP machines incorporate safety mechanisms that prevent the device from turning on if a component is incorrectly assembled, primarily to protect the motor from water damage. The most frequent cause of a power lockout is an improperly seated humidifier water tub. If the tub is not pushed fully into its housing or the lid is not latched, internal sensors will prevent operation.
Check other attached accessories that can trigger a safety stop, such as the air filter cover or a connected data module. If the air filter door is loose or missing, or if an accessory is blocking an intake vent, the machine may refuse to power up. This prevents overheating or drawing in foreign debris. In some cases, a high-leak error message may appear briefly before the machine shuts down, indicating a problem with the mask, tubing, or humidifier assembly.
Next Steps and Professional Help
If you have systematically checked the wall power, confirmed the power supply integrity, and verified all components are correctly seated, the problem likely lies within the internal circuit board. Do not attempt to open the CPAP unit, as this action will void the manufacturer warranty. Instead, locate the machine’s serial number and model information, which is usually printed on a label on the underside of the device.
Contact your Durable Medical Equipment (DME) provider or the machine’s manufacturer with this information. They can offer further diagnostic steps or initiate a repair or replacement process if the machine is under warranty. Most CPAP devices come with a manufacturer’s warranty that lasts approximately two years, covering internal hardware failures.