I have a chimney in my house; my house is old it was built in the early 1900's. The clean out door at the bottom of the chimney in an unfinished basement is rotted off.
My question is where this chimney is not used for any type of fire place. Just as a vent shaft for a gas water heater and a gas heating system. Is a clean out door required? Or can I seal this opening up with bricks.