Up in NJ, installed a Sears system in 1971 when we moved into our A/C-less home, never serviced in 28 years other than filter, then got a new Goodman system installed in 1999 with all the money we saved on check-ups.
that too was never serviced in ~18 years other than filter ...... then moved out in Jan 2017. Only problem we ever had was the 220 junction box outside "broke." We did have a small condensate pump that did die a couple times over the years that drained into the laundry room sink. There was no pipe just some plastic tubing that never clogged. Of course it wasn't used as much as here but still ....... We had 10yr P&L warranty from dealer but never used it. It did not include "checkups."