The pressure regulator controls the pressure of the air coming from the compressor. This component should output air that remains stable at the right pressure. If it is not doing this, the regulator may be damaged and need to be replaced. To access the pressure regulator, you will need the CPAP machine to be switched off and unplugged.

You will find the pressure regulator inside the machine, near the top, at the side.

We can check the pressure of the air coming from the pressure regulator by testing it with a low-range pneumatic gauge.

First, remove the tube where it meets the air filter here.

To test the pressure, the machine will need to be switched back on and running. If the pressure regulator is working correctly, you should expect a pressure of around two to four bars.

If it is higher or lower than this range, you should first try to adjust the regulator slightly. Rotate the control knob at the top clockwise to increase the pressure, or anti-clockwise to reduce it.

You can then test the pressure again.

If you are not able to reach the required pressure level, there is likely to be a problem with the pressure regulator, and it should be replaced.

Also check that the pressure remains stable. If it fluctuates high and low, the pressure regulator is damaged and should be replaced.

To remove the existing pressure regulator, first you need to disconnect the two tubes on either side. For each one, squeeze in the push-fit connector and slide out the tube. Next, unscrew the lock ring.

You can then carefully slide the regulator out through the mounting hole.

To install the new regulator, slide it up through the mounting hole, then screw the lock ring on the hand.

Then reattach two black tubes. Make sure they are firmly secured in the push-fit connectors.

You can then run the machine and check that the problem has been resolved.