Customer called for preventative maintenance. Master service technician cleaned electronic air cleaner. Treated condensate pump with pan tabs. Tested condensate pump operation. Cleaned steam humidifier. Tested humidifier/drain operation. Set humidistat to 40%. Provided and changed dehumidifier air filter and tested operation (left spare on site). Checked operation of UV light. UV bulb should be replaced on spring/summer pm. Checked gas 90% Lennox furnace operation. Cleaned condensate drain and trap. Checked drain operation. Cleaned flame sensor. Checked all wire connections. All amps on all motors good. Blower capacitor holding charge. Blower wheel clean. Gas pressure good. Heat exchanger in working condition. Checked flue vent pipe operation. Temp rise is 52°. System working well at this time. Recommend installing one or two water alarms in room. This would alert anyone if anything starts leaking (I.e. water, furnace, humidifier.