The boost buttons and ventilation systems in modern properties are often misunderstood (especially by new tenants who have just moved in).
These systems that have a "boost" button are called passive air systems. They are usually running all the time and unlike old-fashioned extractor fans, you're never actually supposed to hear these ventilation system working.
As far as we understand, the system switches on automatically when it senses excess moisture in the air, however, you can press the "boost" button to ensure that the system switches on right then and there if you know you will be creating excess moisture (like using the shower or cooking for example).
To test whether your system is working, you can hold a piece a toilet paper by the vent after pressing the "boost" button and see if it gets sucked towards the vent. It should ever-so-slightly be pulled towards the vent and this will show if it's working or not. If it has no effect, then it may be that an engineer visit is required, however, we try, wherever possible, to avoid mistaken callouts because these have to be charged back to the tenants so we want to save you the money at the end of the day. About 20% of reports we receive do not actually require a contractor and it's something that the tenants don't understand or are misusing (by mistake), so it's quite important that you verify the issue before asking us to someone to take a look. This will save you the potential cost of a mistaken callout.
If, after verifying that there definitely is a problem, then please report this to us in the usual way: How do I report a repair or make a request?