I completed a two system heating maintenance. I replaced 1-16x25x1 filter and 1-16x20x1 filter. I cleaned the flame sensor and igniter. I check3d the amp draw on the blower motors,inducer motor and heat strips. I cleaned the flame sensor and checked the igniter on the upstairs furnace. I checked the defrost cycle,amp draw and refrigerant charge on the outdoor unit for down stairs. I checked all safeties and confirmed proper sequence of operation. Both systems are currently heating at manufacturers specifications.