Hi, got this extractor fan installed in bathroom. It’s about 3 years old. The 3rd we’ve had since we brought it as every one develops this fault. It has a humidistat which kicks in and operates as normal. But after a few mins it kind of grinds to a halt and then it sounds like it’s struggling to start again. It’s out of warranty so wondering if it is a common fault and if it can be fixed? I don’t fancy spending another £90+ on another one if it gonna end up the same. Thanks.