Can You Vent A Tankless Water Heater Into A Chimney

Be sure to check your gas water heater annually for cracks or leaks in the flue.

Can you vent a tankless water heater into a chimney.

Yes venting tankless water heater with furnace is possible. I would like to replace my tank type water heater with a tankless rheem rtg 74pv in the same location. Electric tankless water heaters do not need to be vented but gas tankless heaters do. Water heater installed close to the roof framing would need at least 5 long vertical vent pipe single wall vent pipe requires minimum 6 of clearance to combustible materials general rule the chimney should not be outside a window or other house opening.

I would like to vent it into the brick chimney were the heating boiler and the old water heater was vented to. This is because most homes have water heaters and furnace sharing the same exhaust vent. To avert this problem you can vent the water heater to the largest hole in the chimney and cap the remaining holes. The reason is because like a standard water heater they create dangerous combustion gases when they fire.

However it doesn t have to be an expensive hassle to vent. The remaining heat creates a hot exhaust gas that requires metal venting typically stainless steel or thick aluminum. With a condensing tankless water heater you don t need metal venting. The biggest issue is that the condensate is very acidic and will corrode the masonry of a chimney.

The gases contain carbon monoxide. The tankless heater cannot share vent piping with any other appliance and it cannot use a masonry chimney flue for venting. The standard galvanized vent from your old storage tank heater would quickly rust away if your tankless heater vented. Chimney chimney flue must terminate min.

Here s how to vent a water heater to a chimney. The vent pipe must be made of stainless steel designed for venting corrosive gases. Non condensing tankless water heaters typically transfer to the water only about 80 percent of the heat they generate. Technically you can vent your tankless heater through the chimney but only in certain circumstances.

However the key here is to install the vent pipe in the size required by the water heater. It really is not a good idea. Most building codes require 4 inch flue pipes on water heaters. Vent to the outside.