Chimney Clean Out Door Overview
A chimney clean out door is often overlooked and underappreciated. Not installed in all chimneys, it is the back door of a chimney where the rubbish is taken out.
When installed, a chimney clean out door can be behind the fireplace or located outside the house. Before it can be opened, any surrounding mess must be cleaned up. Bricks, caulk, dust, flue tile liner, and other debris accumulate with regular use of the fireplace.
The condition of the chimney flue will be revealed by the debris. For example, concrete at the bottom of the clean out area can indicate damage at the top of the chimney from water, frost or animals. The concrete debris would signal that the chimney is a potential hazard.
When looking up through the clean out door, daylight should be visible from the top of the chimney. Otherwise, the flue is likely blocked due to nests by small animals, collapse of the chimney at different points, etc. A mirror can be useful for inspecting the interior of the door and flue. Upon closing the door, the surrounding area should be inspected for leaks, ash, and other debris.
If the bricks surrounding the door appear old and worn, it would be advisable to replace them before they crumble further and the fireplace exit breaks apart. Using a brick hammer and chisel, either a homeowner or chimney mason can remove the mortar and loose bricks around the opening. The bricks can then be replaced and a new frame added around the cleanout door.
When the chimney clean out door is worn or you wish to install a one in a chimney that lacks it, measure the dimensions of the preexisting door or the available space, then determine the best pattern and door for your needs. The door must be airtight, non-rusting, and provide easy access to the flue.
Many doors, though, are not airtight and are built of a thin material, which rusts and warps easily. Such doors allow air to enter the chimney and create a loss of draft flow. As a result, exhaust gases will condense within the flue to form flammable deposits of creosote. This would be undesirable.
Cast iron and aluminum doors that don’t rust or warp are available. These doors are air tight and insulated. These doors latch shut with a screw that prevents them from being opened accidentally. They are easy to install and come in various colors and sizes.
A chimney clean out door is not installed in all chimneys. For those that have them, the door is a useful feature that allows easier cleaning of the fireplace and flue.