Renew 2 Comfort Club Memberships and complete 2 furnace repair and preventative maintenance check. Find upstairs 2-year-old heating system operating within manufacturer spec. The system may have a problem with tstat, customer wants to keep an eye on Tstat. Did not change filter. Find downstairs furnace 7 years old operating with aworn ignition, worn flame sensor, and system under-fire. Suggest doing combustion calibration, change out the ignition and replace flame sensor. The customer wants to wait. System operating at this time. Replace filter.