Performed pm on oil water heater 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 While performing the maintenance we found the nozzle was very dirty and was dripping inside the blast tube. Also found the blast tube end cone is developing a crack and the end of the blast tube is starting to corrode slightly. Brought the customer down and showed them the corrosion. Customer would like a price on a new burner since the primary control, burner motor, and oil pump are all from the old water heater. Both the nozzle and the cracked end cone will cause the water heater to run dirtier than normal and will cause extra soot and can cause an oil/soot smell. Also found the shark bite fitting going into the water heater is beginning to leak. Took pictures for a repair quote.