Performed pm on oil water heater, furnace, and humidifier Brushed and vacuumed flue pipe and heat exchanger Replaced oil filter, nozzle, and strainer Checked all electrical connections and safeties Performed combustion and smoke tests Furnace- 9.7%o2 0 ppm co 0 smoke Water heater- 9.0%o2 4ppm co 0 smoke Replaced humidifier pad and tested operation Recommend replacing the water heater. The water heater is from 2004. Oil Water heaters typically last around 15 years.