Arrived on site to preform a maintenance on two Goodman systems. Turn downstairs unit into heat mode and verified the proper heating sequences for both units. Took an inducer draw in both units, both motors were in range. Homeowner states the filters were both recently changed and how the system has not been running in over a month as the customer has not been home in that time. While doing my maintenance I did discover a lot of dust on the inside of both units, recommended the homeowner get a pull and clean on both blower wheels as they were layered with dust, which can cause the motors to overwork themselves. Homeowner will take it into consideration for the next visit. Continued with maintenance, inspected all electrical connections and measured volts and amps of each. Explained to homeowner about surge protection for indoor units with rolling brown outs. They will take it into consideration for next time. Static pressure for both units was I range. Checked condensate drains on both