Oil Burner Exhaust On Metal Roofs Rusting

Working on our 133 year old house i found the furnace exhaust pipe rusted out.

Oil burner exhaust on metal roofs rusting.

The instant i capped my furnace flue rust like deposits began to condense on the cap drip to the chimney crown and then down to stain my metal roof. To remove powder and soluble rinse it with water properly. In sum corrosion and stains on and around metal chimneys include rust flue gas deposits and corrosive condensates though not primarily from oil dye as you suggest rust stains from contact between dissimilar metals occasionally sulfates the main component and even bacteria in oil fired systems. After multi visits with riello and other consultants we changed the burner to a beckett af2 and my combustion parammeters were perfect.

My furnace guys say the stains are very dark for sulphur but they concede that they can t suggest anything else that it could be. Light rust does not get removed by simple wiping since it is firmly bonded to the metal surface. Rust is the result of oxidation that occurs when metal oxygen and water mix. My chimney company say it s sulphur deposits.

First and foremost remove any oil grease and dirt present on the rusted metal. He had a soot up so they cleaned it and gave the burner more air lower co2 i was called in and noticed they could never get higher then 10 co2 without smoke. If cracks occur in a heat exchanger because of the weakening. You don t want this to occur to your furnace especially along the heat exchangers.

The great danger of rust to metal is that it eats away at the metal and eventually causes it to crumble and flake away. Talking about how i fixed it.