What to do if your HVAC is flooded

Flooding happens across the United States almost every day of the year and it seems like it’s happening in Tennessee more often. Flooding means more than high water on roads. It can also damage your home and HVAC system.

Heat pumps, air conditioners and other parts of your central heating and air system can be easily damaged by too much rain. It’s often safer to replace rather than repair a system that has seen water damage.

HVAC units

Many electric HVAC units can withstand about a foot of water before components are damaged. They are built to handle most weather situations, being designed to be outside.

But if too much water gets in, it can damage the electrical components. If you are worried, look outside the unit and remember, the lowest electrical component is the first point of failure. If that gets wet, then you will need to replace the unit.

Many gas heating units will sustain serious damage even before that point. Most gas units have a gas burner or heat exchanger near ground level. So it doesn’t take much water to cause significant damage.

The water can cause valves and controls to corrode and even a thermostat to break.

In addition to damage to the wiring and gas components, flood waters can also cause refrigerant leaks. Even if there aren’t leaks, the refrigerant system should be cleaned and disinfected by a trained professional.

The water will also contaminate any insulation in the unit. This can cause rust and mold to form inside the unit.

Flood waters can contain a multitude of contaminants. There is no way to salvage insulation from that.


That’s not to mention the possible damage to ductwork. If it is under your house, it probably got wet.

The best case scenario is it was just the insulation, which will need to be replaced. There is no way to salvage wet insulation.

Worst case is water penetrated the ducts. It is possible that it can be cleaned, dried and disinfected but, most likely, it will need to be replaced.

The silver lining is, if it is done right, your ducts will be sealed and the insulation improved, which will reduce your costs to heat and cool your home.

If your home has been damaged by flooding, call the experts at Tennessee Mechanical Corporation to help today.