Thanks everyone for the feedback. I was seriously considering billing this back to the tenant until I read @Jon Holdman post and my wife essentially told me the same thing. I didn't explicitly show the tenant how to use them as I'm out of state but I did explain them to them. Like Jon said, things a lot of the time gets lost in translation. I'll eat the cost on this one. I was assured by the HVAC guy he thoroughly explained the dampers and how they work to the tenants so this shouldn't occur again.
I was also a supporter of the maintenance fee deductible but after reading on it some more, I now believe its a bad idea as tenants are more likely not to report serious issues which in turn will cause the LL a serious outlay in cash eventually. Thanks again for all of the feedback!
