How familiar is this: A homeowner shops around for the lowest bid on a new central air or heat pump system. The equipment works initially, but the compressor wears out prematurely. The homeowner says he never changed the filter or performed other essential maintenance; he didn’t know he was supposed to.
Part of the low cost, however, is due to the fact that the installing contractor has lower overhead because his installers have not been properly trained in fundamentals, such as checking the refrigerant charge. The homeowner eventually calls you to fix or replace the unit.