I know this isn't really an AIBU but it really is worth telling everyone about.
Even though it's quite boring.
Our Miele tumble dryer was constantly turning itself off and beeping, complaining about its airways being blocked (even though we cleaned the fluff off them very assiduously every day** and even took out the whole big filter at the bottom of the machine and rinsed that out and everything).
So we called out a repair guy, who shrugged his shoulders and said he couldn't see anything wrong with it.
So then we called out a specialist Miele guy and he told us that not only did we need to clean the fluff off but also we should have been actually washing (with washing up liquid) the little detachable filters that go just in front of the drum.
Who knew?!!
Call out charge of over £100 for some guy (very nice man but still) to show me how to use some Fairy liquid.
So I thought I'd better tell all of you in case I'm not the only ignoramus.