Upon arrival for double tune up, I asked homeowner to show me to thermostats and indoor access to units I asked if he had filters and a container of bleach or white vinegar and he provided both I began with checking downstairs system which had good delta readings and new filter installed I then checked blower motor which was clean and in good condition Checked evaporator coil which was clean and in good condition Checked drain line with vinegar and 1 gallon of water, line had no backups Checked and tightened a few loose electrical connections Lastly I switched unit to heat and checked sequence of operation which all was working well and inducer motor has good amp draw Switched to upstairs unit and found everything to be in same good operating condition and new filter installed Moved to outdoor condenser units what I first checked safety disconnects, both are in good condition Then removed condenser fans and checked motor on both units, both in good condition Cleaned condenser coils