Most of the older homes in Kansas City will have a brick and mason chimney to vent their combustable appliances such as the water heater and furnace. During the last decade, many furnaces have been replaced with high efficiency units which are vented differently than a traditional furnace.
A high efficiency furnace is vented with pvc pipe and generally runs out the side of the house instead of through the chimney. This can create a problem for the other appliances that are using the flue to vent carbon monoxide. A flue for a water heater or furnace has a natural draft that allows the appliance to vent freely. In order to maintain this natural draft, the flue must be sized correctly. When an appliance is either removed or replaced with a style that vents differently you must consider the impact that it will have of the flue’s ability to vent.
The same goes for a water heater, if you are converting your standard water heater to a tankless water heater you should have a licensed plumber inspect to ensure their won’t be any venting issues.
In either case, if you install a high efficiency water heater of furnace you may need to line the inside of your flue to properly fit your load.