Gas Furnace And Water Heater Chimney

Yes with some provisions and restrictions an oil and a gas fired heating appliance may be vented into the same chimney flue.

Gas furnace and water heater chimney.

That s a sign that hot gases are backdrafting toward the unit. The lower btuh of a gas water heater compared with a heating furnace or boiler will very often be unable to heat the chimney interior sufficiently to develop a draft. Flue gases temperature in older low efficiency furnaces 78 and less efficient was sufficient to elevate chimney flue temperature to the point which guaranteed proper draft. In some homes gas water heaters also vent into chimneys.

Allow water heater to run continuously for 10 minutes. But many don t realize that a gas heating appliance whether it is a furnace boiler or even a water heater relies on the chimney for proper venting of the exhaust. If water heater and a gas furnace share the same vent reduce the thermostat setting for the furnace so it does not run during the test. A backdrafting water heater is arguably an even bigger problem than a backdrafting furnace.

Chimney problems gas water heater heating system. All water heater venting systems use a vent duct or pipe also called a chimney or flue to bring exhaust gases from the water heater to the outdoors. Run enough hot water for the water heater start heating. To avert this problem you can vent the water heater to the largest hole in the chimney and cap the remaining holes.

To test for proper water heater venting. How to know a gas water heater is venting safely. In some jurisdictions an oil fired heater and a gas fired heating appliance such as an oil fired heating boiler and a gas fired water heater may be permitted to share the same flue provided. These should be tested as well especially if you see melted or melting plastic grommets on the side of the water heater.

Gas water heater and furnace chimney flue size calculations the basic method for the chimney flue size calculations is the seven times rule applies to natural draft and or fan assisted type appliances vented into the same chimney. The duct may be metal or plastic depending on the type of vent system. When connecting a new regular type known as category 1 type gas appliances furnace water heater with efficiency slightly below 83 old chimney flue size might need to be decreased with a new liner. 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.