Renter never changed out furnace filter and froze up A/C, should they pay?

[Steven Fowler]

I have some very good, professional renters in my place. Have never paid late or had any issues. They have been there for 2 years. The wife called me yesterday and told me the a/c was not working. Company comes out to take a look and calls me and tells me the furnace filter hasn't been changed out in a long time, like years, and it froze up the whole unit. The lease specifically addresses maintenance like this. The bill was $180. Should I just suck it up, since they never give me any issues, ask them to pay the entire bill, or ignore the issue until they move out and address it with their deposit?

Thanks!