Chimneys and Chimney Troubleshooting
A chimney used with a coal furnace should be of sufficient height and area to meet the requirements of the furnace. The top of the chimney should be at least 2 ft higher than the highest portion of the roof within 10 ft horizontally. There should also be a minimum of 3 feet between the top of the chimney and the point at which it passes through the roof (see Figure 13-10). For best results, only the furnace should be connected to the chimney. Read the section Chimneys in Chapter 11, “Gas Furnaces.”
A chimney connected to a coal or wood burning furnace must have a cleanout door at the bottom. This door allows ashes and other residue to be removed from the bottom of the chimney. The cleanout door must have a tight fit. It must never be left open during the combustion process.
The chimneys used with coal furnaces are basically the same as those used with gas and oil units. Read the section Chimney Troubleshooting in Chapter 11, “Gas Furnaces” for a description of common chimney problems and suggested remedies.
