Performed a heating pm on an oil furnace and oil hot water heater. Brushed and vacuumed. Replaced the oil filter, nozzles and strainers. Started and checked the safeties. Performed a combustion test. Furnace- 4.0% o2, 30 ppm, 87.8% efficient Hwh- 6.8% o2, 25 ppm, 83.7% efficient System is operating properly.