Performed a two system maintenance checking heating, checked inside electrical and mechanical components, checked gas pressures which upstairs was at 3.6wc adjusted valve to 3.5wc, downstairs was at 3.8wc adjusted to 3.5wc. Cleaned flame sensor, checked safeties, amp draws, filters need to be changed out. Homeowner said they would take care of it. Checked UV bulbs, ductwork connections. Both systems are heating properly at this time.