Oil fuel is pumped into a tank that is either outside or in a basement and distributed to the oil boiler when the thermostat calls for heat. The oil is burnt just like natural gas or propane, but requires specific venting when burnt because of the greater amount of carbon monoxide production. Carbon monoxide is odourless, tasteless, and can not be seen, making it a very lethal gas. The flue regulations are in place to protect and prevent poisoning and provide safe and comfortable heating for everyone who uses oil heat.
Type L Vent
A type "L" listed chimney has an inner layer made of stainless steel, an air space that serves as an insulator and a thermal break, and an outside layer made of galvanised steel. These chimneys are specifically made for oil burning appliances. They require 1 inch of clearance from combustible surfaces or materials.
A barometric damper opens when the boiler burner fires up to pull air through it and prevent back drafting. The barometric damper should be located on the mostly horizontal section of the boiler flue close to the vertical L vent or masonry chimney flue.
Exhaust Flue Support and Clearance
All horizontal flue sections must be supported from the ceiling every 4 feet by non combustible supports. The horizontal section of flue that is single wall pipe must maintain 18 inches of clearance from any combustible material.