Combustion gases that back-draft into a house may leave a dark residue on the top of the water heater. The presence of soot is an indication of backdrafting, although its absence does not guarantee that backdrafting has not happened. A carbon monoxide analyzer can be used to test for backdrafting of that gas.

Power Burners A single acting draft control for oil maintains that negative pressure. A power burner designed to burn natural or LP gas operates in the same manner.

An Uplifting Experience. A natural draft furnace is one that uses natural atmospheric pressure to force the waste gasses of combustion out through the ventilation system. As the fuel in the furnace burns, it creates hot air as well as combustion byproducts, such as carbon monoxide and nitrogen dioxide.

Most furnaces will have at least 2 internal drains, typically one for the heat exchanger and one for the vent, usually at the inducer outlet or on the inducer housing. All condensate drains go into a trap. The condensate trap is absolutely mandatory for a high-efficiency gas furnace.

However, a furnace water leak isn’t something you’d want to ignore. Furnace water leaks can not only damage your home’s flooring and carpeting but also erode concrete and certain metals, due to its potentially acidic nature. Anytime you see a water leak of any kind, you should take care of it as soon as possible.

A clogged AC drain line symptoms include:

1. Musty, moldy smell near your indoor unit or in air from the registers/vents.
2. Standing water near the indoor unit.
3. Water damage in areas near the indoor unit.
4. AC system is not cooling your home.
5. AC system shuts down or doesn’t turn on.

To squeeze 90% or more of the heat energy out of a gas flame, you have to condense the water vapor out of the exhaust into liquid form and recover the heat of evaporation from it. It turns out, however, that when you condense out the water vapor, the nitrogen products — the NOX — come along with it.

Clean the pan with soap and water. Find the condensate drain outlet which might be located outside your house near the foundation. Many times the clogged drain can be cleared with wet/dry vacuum suction. You can also try removing the clog with a plumber’s snake.

HomeTips.com says a high-efficiency furnace can produce as much as 5 or 6 gallons of water from condensation each day. Most of the time, condensate pipes are set up to carry condensation outdoors through a hole in an exterior wall. The water is able to drain harmlessly into the ground.

Although some HVAC units and furnaces have what’s called a “condensate pan” beneath them to catch drips, most modern units entrust the condensate line with effectively funneling all residual water outdoors where it can evaporate into the air.