yes you can reline a chimney yourself but its easier with help
when our heating system was changed from a back boiler to a wall mounted one we had the back boiler removed so as to revert to a 1st class chimney, so we could have a coal fire if required, and the flue liner was taken out.
class 1.
A flue liner protects the bricks or masonry that makes your chimney for your fireplace. It can also protect any wood that it is close to. Flex King offers a flue liner for around $400.00.
the flue pipe from my boiler runs directly to the hole in the chimney
"A clay flue liner is a liner for your fireplace. This would be helpful in case you needed to clean your chimney it makes it easier to clean, and less likely to cause fires."
A flue liner is a flexible sleeve inside the pipe that carries the combustible products, such as smoke, up from the fire away from the living area, and into the atmosphere, outside the house. A liner is needed in case the flue is cracked or damaged, causing the smoke to stay in the house, or causing cold wind from the outside to come into the house. A flue liner is added protection to keeping the house safe from fumes.
plumbing your toilet into the boiler
Possibly the boiler is firing oil and thus the soot from the oil is spilling back into the gas flue
ATMOSPHERIC BOILERa boiler on which combustion air/flue gases are drawn through the boiler without a fan.(Taken directly from the Crown Boiler Co. web-site.)
More than likely a local business specializing in chimneys and/or rooftops. These professionals can give more detailed information on the size and shape of flue liner needed. These can be found in the shops of chimney stores and on online companies that sell flue liners.
If the boiler fuel contains Sulphur (and most do) combustion products in the flue gas will include Oxides of Sulphur (SO2 and SO3). SO3 combines with water (H2O) to make Sulphuric Acid (H2SO4). If the temperature of the flue gas falls below the dew point, the combination of the acid with the moisture in the flue gas causes corrosion of the flue gas duct work. Bypassing the economiser in the early stages of a boiler start keeps the flue gas temperature above the dew point.
Flue gas is a type of exhaust gas that exits the atmosphere through a pipe often called a flue. Flue gas can be seen exiting power plants, a fireplace, oven, boiler or steam generator.