I have been in the same rental dwelling for several years.
In the years that I have lived here, I have only ever had one issue with the heating plus cooling system.
Because there is only window units plus space heaters, there is not much that can go wrong. The weather in the region where I live is mild, plus gets moderate in the summer. The dwelling I live in is well shaded plus there’s a lot of trees over the house. The daylight never makes the dwelling too tepid plus I am delighted that I live in a dwelling that doesn’t get baked in the daylight all day. When I noticed that something was wrong with the AC, I acted fast. I know I didn’t want to be without A/C for more than a few afternoons, plus I was looking forward to a new A/C unit. The ones that were in the dwelling before the replacement were 10 years old. The A/C units were rusted plus had slowly stopped blowing chilly air. It wasn’t that much of a problem until a new family moved in next door plus took down one of the trees that was providing much of the shade that was keeping the dwelling cool. I didn’t notice how much daylight they were blocking until they were gone. The A/C units were replaced in about an hour plus my good friend and I were able to sleep comfortably that evening regardless of the lack of shade in the backyard.