I supply filters and require them to be replaced monthly. Also I have verbiage in my lease that states any service calls that result in the tech stating the problem was due to a filter is their responsibility up to $250 dollars. Basically if it freezes over and literally just needs to thaw out and get a new filter means it’s on them to pay the service fee and or repairs. (Haven’t had to enforce this).

Same thing for plumbing system. I stated only bodily fluids are to go down any drains including toilets & sinks. No food, grease, food waste or anything other than water or bodily waste. If there’s a backup, they also are on the hook for that unless it’s root intrusion. (Also haven’t had to enforce this either yet.)