Arrived onsite for heating maintenance 4 gas fired furnaces with 2 humidifiers. Turned on all thermostats and Confirmed operation of all heating systems Basement Furnace Left: Turned on humidifier and set to winter. Panel 45 in good shape. Brushed and Wiped down furnace blower cabinet and gas burners. Burners fired and are in good working order. No visual impingement detected. Checked electrical. Cleaned flame rectification system. Measured 50 degree heat rise. System is operating as it should. Basement Furnace Right: turned on humidifier and set to winter. Panel 45 in good shape. Brushed and Wiped down furnace blower cabinet and gas burners. Burners fired and are in good working order. No visual impingement detected. Checked electrical. Cleaned flame rectification system. Measured 47 degree heat rise. System is operating as it should.