Make guests aware of the procedures they should follow, should the carbon monoxide alarm go off whilst they are staying. Provide guests with emergency contact numbers in your welcome pack as well as instructions for how to use any of the above appliances (including portable back-ups). For example, avoid using any of these appliances being used near open windows.
Alarms should be installed on every floor of your property, ideally outside of rooms where guests may sleep so it is easily audible. Make sure to test these alarms every month. Appliances should also be cleaned and inspected regularly, and exhaust flues should be kept open. Fire vents should also not be closed until a fire is completely out.
This guide in non-exhaustive and there are other ways you can take measures in your holiday home. Please do read other sources, for example our Airbnb partner channel help guide.