Arrived on site to perform heating tune up on 2 2015 lennox units. Both location attic. Client shined up on maintenance plan and used today as her first visit. Cycled both heaters on and both are operational. Client replaced filter a bit ago. Blower motor and wheels are both good. Slight dust. Motor are good. Inducer motor are or good in range. Temperature rise is good on both units. Black flex ducting found. Drain lines are good at this time. All safety switches are operational. No protection on either unit. Cycled both units and went over how units are running and recommendations with client and she is aware and did hold off. Cycled unit to ensure unit is heating upon departure.