Sometimes, the challenges are unique, not all are this friendly

Many times, if maintenance is "defered" to a later time, we find critters will move in.  Often they are the cause for a system failure.  Mice will chew on electrical wiring, bees build nests, other insects just clog up the works.  By having your system regularly checked, these nuisance outages can often be avoided.  Also, remember pets need to be kept away from your outdoor unit as coil damage can result when your puppy confuses the A/C with a fire hydrant.