Venting Hot Water Heater And Furnace Through Chimney

The exhaust gas temperature of modern gas furnaces and water heaters is much lower than past appliances because much more heat is harvested so you waste less money up your chimney.

Venting hot water heater and furnace through chimney.

When venting a gas water heater to a chimney be aware that holes in the chimney can prevent a good draw on the water heater causing downdrafts and presenting the risk of carbon monoxide poisoning. When venting two appliances separately into a common chimney always install the smaller flue pipe appliance with lowest gph input at a higher point into the chimney than the larger flue pipe for the appliance with the largest gph input. These should be tested as well especially if you see melted or melting plastic grommets on the side of the water heater. Water heater ducts may lead directly outdoors or they may tie into a larger vent duct that also serves a gas or propane furnace or boiler in the home.

Illustration above an unused chimney flue or masonry enclosure may be used as a passageway for the installation of the water heater vent pipe. A backdrafting water heater is arguably an even bigger problem than a backdrafting furnace. Venting through existing chimney. In some locales fire officials also permit two gas appliances to vent into a single flue when the heaters are on different floors as we see in carson dunlop associates at reviewers sketch.

Two gas fired appliances such as a water heater and heating boiler may be vented into the same flue if your local jurisdiction approves of that installation. Before connecting a vent to a chimney make sure the chimney passageway is clear and free of obstructions. Traditional masonry chimneys were designed and sized to vent very hot flue gases from old coal wood burning or low efficiency gas furnaces. The duct may be metal or plastic depending on the type of vent system.

Atmospheric venting refers to a system in which exhaust from the water heater naturally rises out of the appliance s combustion chamber then travels up through a standard chimney style flue that. The conditions explained in this post also apply to the wood burning appliances. To avert this problem you can vent the water heater to the largest hole in the chimney and cap the remaining holes. The area around the flue piping should be sealed where it enters the chimney.

In some homes gas water heaters also vent into chimneys. Proper furnace water heater venting is an extremely important issue which depends on the performance of the house chimney chimney flue or other exhaust assemblies. Refer to figure 2.