Received a work order to meet up with Ed (GoGreen). Arrived at the property and observed the homes oil fired boiler with soot all over the place. I began to perform a thorough methodical process of taking the boiler apart to diagnose what was causing the apparent issue. I replaced the oil tank filter along with the fuel pump strainer. Next, I opened up the burner assembly and removed the gun. I took the gun apart, to degrease all components and wire brushed for better light off. I reassembled the gun reset the electrodes to factory specs and replaced the nozzle with a 1.10/60B. Reassembled the burner. I removed the flue pipes and opened up the combustion chamber (heat exchanger) to the boiler. Boiler had quite a bit of debris. Upon inspecting the flue pipes, the elbow attached at the ceiling tells the story of debris falling down the stack and accumulating at the elbow. I would almost say, that someone serviced the stack and did not remove the flue pipes connected to the boiler. I brus