In my flat, there are two wall-mounted extractor fans that serve the common purpose of removing warm and damp air. You’ll find one in the bathroom and the other in the kitchen.
My bathroom fan has always worked well. But in the kitchen, the fan has often been very slow to start (if and when it decides to do that much) and, while it is spinning, it often sounds as though it’s ‘knocking’ and would simultaneously create a rhythm of its own.
During his recent visit, I raised this issue with my landlord, who suggested the first port of all should be to open it up and clean it out. I volunteered to do this in my own time and this is the short story that documents the process.