Arrived at customers house to preform two 20 point furnace maintenance inspections. When we arrived on site the customer had both units on in heat. We went into the garage attic and started on the system there. Upon first glanced I noticed the ducting was a little undersized. This was mention to the customer. Next we looked at all electrical connections and took our amp draws and checked limit switches. Both were looking good and were within range. Next we took a look at the filter, 16x25x5 merv 16 was looking good and did not need to be replaced at this time. Flushed condensate drains and made sure they drained properly. Checked flue vent and gas piping for any leaks. There were no gas smells or leaks while system was running. Next we headed down to the downstairs unit in the basement/craw space. At first glance the unit looked like it was running properly. We opened the system up and started taking our electrical measurements. All electrical on downstairs outside unit was good and