The CPAP machine’s filters are essential for protecting both the patient and the machine by blocking dust and dirt. Before checking the filters, make sure the machine is switched off and unplugged at the wall.

If the CPAP has an automatic voltage switcher attached like this one, you should also unplug this.

The gross particle filter is positioned in the panel at the back of the machine. You can carefully pinch the filter and prise this out. Check the filter for signs of wear and damage. If it is badly worn or heavily soiled, throw it away and fit a new one. If the filter is in a good condition, you can clean it and reuse it.

Install the spare filter while you wash this one.

To put the gross particle filter back or install the spare one, simply pinch it and press it into position.

To clean a dirty filter, first, you tap or blow out the dust and debris. Make sure you blow outwards from the cleaner inner side.

Next, place the filter in warm soapy water and swirl gently to remove and wash out the dirt. Then rinse with clean water from a tap, again, from the clean side to the dirty side.

Then allow the filter to dry completely. Do not do this in direct sunlight. Once completely dry, store the filter as a spare.

To access the fine particle filter, first remove the panel at the back. This is opened by a catch at the top.

This filter is held in a cartridge, which you can remove by prising upwards. You might need to wiggle it to pull it free of its seal.

Inspect the filter. If there are signs of damage, discoloration, or the filter clogged with dust, you will need to fit a new one.

This filter cannot be cleaned. The whole filter in its plastic cartridge is replaced as one unit.

When the filters have been cleaned or replaced, plug in the CPAP machine, switch it on, and check that it’s working properly.