@Brady42 In very limited circumstances, Airbnb's so-called "Host Guarantee" (which is not what it sounds like - read the fine print carefully) can work as a supplement to your own private STR and contents insurance policy, when damage has demonstrably been caused by a guest. By no means should you ever consider it an insurance. There is no such thing as a website that gives you free insurance coverage for broken appliances simply by posting a listing on it. That would be a pretty dumb business plan on their part, wouldn't it?
When a tenant alerts you that the vacuum is malfunctioning, I don't recommend jumping to the conclusion that they've damaged it. The first thing I would do is schedule a time to go to the property and inspect the vacuum myself. I keep the product manuals for all my devices in a file in case they might be needed for troubleshooting, but most of these manuals are also available online too. The issue could turn out to be a very easy one to fix, but it's better to do it yourself than let the guest start taking your stuff apart and risk making it worse.
If you can't resolve the issue quickly, or you're hosting remotely, provide the guest with an affordable replacement item and ask that they store the defective one securely until you're able to attend to it.
Whatever you do, don't make your guest feel penalized for informing you about issues and trying to keep your home clean. That would be very much the opposite of good hospitality.