Performed pm on oil boiler 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 O2 7.9% 0 ppm While performing the maintenance we found the corrosion on the side of the boiler has progressed farther. Also found a gasket on the side of the boiler has split and is letting extra oxygen into the combustion chamber. Patched the hole with furnace cement but recommend replacing the boiler as soon as possible before any issues arise. Took pictures and measurements for a replacement quote.