What do you HVAC pros consider a residental PM to consist of ?
Filters , certainly , but home owners can do that , if they will ?
Inspection of the condition of ducts ?
Check for oily spots that might indicate leaks ?
Inspection of the condensor for stopped up air passages at the coils ?
Do you do the same for the A-Coil , on the furnace ?
Do fan motors have a place to oil them , any more ?
Check temperatures to verify system performance ?
IR scan of the electrical ?