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Can a Furnace Survive a Flood? What You Need to Know

Your furnace is one of the most expensive (and useful) appliances in your home. When you buy one, you expect it to last for decades. Therefore, if your home is prone to flooding, you’re right to be concerned about your furnace’s chances of survival during a flood.

A furnace can survive a flood, but it can get severely damaged if water gets inside and drenches the internal components. To maximize your furnace’s survivability, take steps to keep water out of the furnace, like moving your furnace to a higher floor or installing a floodwall around the furnace.

It’s important to have a plan for both flood prevention and damage control when it comes to your furnace. I’ll walk you through both in the rest of this article.

How Do You Assess a Furnace After a Flood?

If your home has been flooded, you’ll probably have to move out until the waters have receded, and the authorities have indicated that it is safe to go home.

When you return home, you’ll want to see if your furnace has survived the flood intact. Here are a few things you can do: 

Assess the Furnace Carefully

If your furnace is installed on a higher floor, it would likely not be damaged by a flood. However, if your furnace is installed in your basement, its chances being damaged would be much higher. 

The first thing you would want to check is whether water has entered into your furnace.

Your furnace might be in good condition if flood water has only risen to a few inches of your furnace.

However, if the floodwater has risen to more than the halfway level of your furnace, it’s probably been damaged.

To be safe, you should avoid touching the internal components of the furnace. Leave that to a professional.

Call In an HVAC Professional to Inspect the Furnace

If you suspect your furnace has been damaged by floodwater, it is important to call in a qualified HVAC professional to inspect the furnace. Furnaces are complicated appliances, and you won’t be able to diagnose the furnace’s level of damage if you don’t know what to look for.

Clean or Replace Any Water-Contaminated Filters

Floodwater often brings with it silt and dirt, which can be lodged into your furnace’s internal components.

The furnace filters are particularly susceptible to being contaminated by bacteria and fungi if floodwater has entered them.

Even if your furnace filters appear clean upon inspection, they are still susceptible to fungi growth later if they have been wet. If this happens, the quality of air in your home would be negatively affected. 

The HVAC professional should be able to advise you on whether the filters of your furnace need to be cleaned or replaced. 

Replace Damaged Components

If the HVAC professional has determined that the flood damages your furnace, the next step would be to replace all the components that have been damaged.

It might sometimes be cheaper to replace the whole furnace instead of replacing every damaged component, which might cost more. The HVAC professional should be able to advise you on the most economical way forward. 

How Do You Prevent Your Furnace From Getting Damaged by a Flood in the First Place?

As the saying goes, prevention is better than cure.

Before you get to the point of needing to replace your furnace that has been damaged by floodwater, there are two simple steps that you can take to make it more resistant to floods: 

Move Your Furnace to a Higher Floor

When a flood occurs, the basement in your home is the room most susceptible to being flooded. Remember, water always flows to the lowest point, and the lowest point in a home is always the basement. However, this does not stop a large number of people from installing their furnace in their basement.

If your house is prone to floods, it might be good to hire a contractor to install your furnace on a higher floor, such as in a utility room on the second floor or the attic. This will safely move your furnace away from the danger zone. 

Install a Floodwall 

If you can’t move your furnace to a higher level, consider hiring a contractor to install a floodwall.

A floodwall is a wall that can be built around your furnace to prevent it from getting damaged should a flood occur. A well-built floodwall will stop floodwater from entering into your furnace even if water levels have risen significantly. 

When installing a floodwall, it is important to ensure enough space for future service maintenance. 

Final Thoughts

A furnace can survive a flood, but if water has entered into your furnace, it would be best to have an HVAC professional come in and assess it thoroughly to ensure that it is truly safe for future use.

Consider cleaning or replacing any damaged filters to prevent bacteria and fungi from growing and negatively affecting your home’s air quality.

Any other damaged components should also be replaced. However, it might be cheaper to have the whole furnace replaced if many components have been damaged. 

Alternatively, you can also take proactive steps to prevent your furnace from flood damage. You can choose to have it installed on a higher floor or install a floodwall around your furnace if left in the basement.