Performed a heating pm on an oil boiler. Brushed and vacuumed. Replaced the oil filter, nozzle and strainer. Started and checked the safeties. Performed a combustion test. 8.5% o2, 30 ppm, 0 smoke, 82.3% efficient System is operating properly. There is a couple of sections of flue pipe that are getting soft (easy to squeeze), recommend replacing them in the future. Also there was dryer lint around the boiler, recommend checking the dryer connections. There is corrosion around the bolts of the domestic water coil from a previous leak. Recommend replacing the coil gasket.