Does the refrigerator have air or water filters that need to be replaced? How do you do that and how often?
Is there a maintenance schedule for pulling it out and cleaning dust from any heat dissipating elements?
How often should the water hose for the ice maker be checked and replaced?
Is there a trick to removing shelves for cleaning?
How would you even know when to take it in for an oil change??
That’s how I’d answer if I set something up years ago and it was stable and never required me to come tinker with it.