Arrived on site to perform fall tune up on a 2 heaters. A 2019 Lennox unit and a 2005 York system. Cycled both systems in heating mode to ensure system operating upon arrival. Both good and nest operational. Found new ducting used on both systems and okay condition. Inspected new unit. Filter dirty and recommend replacing to reduce amount of dirt entering system. Other filter was just replaced by client. Blower assembly is good and slight Dust on new unit. Older unit due to access unable to open up blower compartment due to way system is designed but possibility of some dirt accumulating over the 15 years of operation. Motors amp drawls are both in range. Evaporator coil are good. Older unit haze some debris due to areas home is surrounded by which is always windy and a lot of dirt entering home. Drain lines are good. Found no protection on either unit indoor and outdoor. Recommend adding surge protectors on unit to protect system from electrical surges from power outages and high vol