Performed pm on oil furnace 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 8.9%o2 1ppm co 0 smoke While performing the maintenance we found the oil tank is starting to leak from the bottom seam where the oil tank valve is. Showed the customer the leak and put some oil absorbing powder and pads under where the leak is. Took pictures and measurements for a replacement quote. Has about 1/4 tank of oil.