Furnace And Water Heater Venting

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.

Furnace and water heater venting.

With a replacement high efficiency furnace the existing vent pipe does not work for water heater only because the vent is too large. This is called a common vent configuration. 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. In many cases the exhaust from the larger appliance heats up the common vent improving the flow of the water heater vent.

Because of their unique construction power vent water heaters are virtually impossible to backdraft. Many building codes mandate that once modified or changed all fuel burning appliance vents must be sized according to code. The vent for your recently orphaned water heater may not have been checked by the furnace installer. High e furnaces have separate venting.

As far as sealing off the ventilation in your crawlspace very bad. 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. The result is a back draft of combustion products out of the water heater s draft hood and into the building. The old vent pipe is too large because it served both the furnace and water heater.

You have 3 gas burning appliances that must have a constant fresh air supply to support clean and complete combustion process. Power vent water heaters have quickly become the standard for newly constructed homes equipped with built in fans that push the exhaust gas out of the vent through a powered fan. The photo below shows typical combined furnace water heater venting. It carries the solution down the chimney furnace water heater vent pipe and evaporates leaving the salt deposits on surface joints.

Traditional gas fired forced air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes or chimneys. Consequences of improperly assembled vent pipes problematic chimney flue deteriorating chimney walls can be sometimes fatal fire and carbon. Gas water heater vent codes standards.