The short answer
Why You Should Wait
Floodwater often carries mud, debris, and contaminants that can get inside the AC unit. Water can short-circuit electrical components, damage the compressor, and ruin the insulation inside the system. Turning it on before it dries out can cause sparks or even a fire.
Even if the unit looks dry on the outside, moisture can hide in the ductwork, coils, and drain pan. Running the AC then pushes humid air through your home, which can raise indoor moisture levels. That makes mold growth more likely in walls and carpets.
Checking for Water Damage
Before you think about turning the AC back on, look for obvious signs of flooding. Check the outdoor unit for mud or standing water around it. For indoor units, inspect the vents, filters, and any visible wiring for moisture or debris.
If you see water stains on the ceiling near the air handler, or if the unit smells musty, that points to water intrusion. Do not try to clean or dry the electrical parts yourself. An electrician or HVAC professional can safely assess the damage.
- Look for mud or water stains on the unit
- Check the air filter for dampness or debris
- Smell for musty odors from the vents
- Inspect the electrical wiring for corrosion
- Note any unusual sounds when the unit is off
Health and Mold Risks
Floodwater can carry bacteria and mold spores. When you run the AC, those spores can blow into your living spaces. This can trigger allergies, asthma, or other breathing problems. See a doctor if you feel unwell after being in the flooded area.
Mold can start growing within 24 to 48 hours on wet surfaces. The AC system itself can become a mold reservoir, spreading spores every time it runs. Professional cleaning and drying of the system may be needed before it is safe to use again.
What the Pros Usually Do
Local water damage pros typically start by inspecting the AC unit and its electrical connections. They may remove the blower motor, clean the coils, and dry out the drain pan. In some cases, they replace damaged insulation or wiring.
The work often involves drying the surrounding structure too. If walls or ceilings got wet, they need to be dried before the AC runs again. This helps prevent hidden moisture from causing long-term damage. The pros can also recommend when it is safe to turn the system back on.
Insurance and Your Policy
Your homeowners insurance may cover flood damage to your AC system, but it depends on your specific policy. Check your policy documents to understand what is included. Some policies have separate flood coverage or exclusions.
Document the damage with photos and keep records of any repairs. Policies vary, and your insurer decides what is covered. If you have questions, contact your insurance company directly. They can tell you what steps to take next.
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Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (801) 383-0232Frequently asked questions
Can I run the AC on fan mode only?
Even fan-only mode can pull moisture from the ducts and blow it into the air. If the system has water inside, it can spread mold spores. Wait until a professional has cleaned and dried the unit before using any setting.
How long should I wait before using the AC?
There is no fixed time. It depends on how much water got into the system and how long it stays wet. A professional can test the electrical parts and dry the unit properly. Acting quickly to get an inspection is the right step.
What if the AC was off during the flood?
If the unit was off, it might have less water inside, but moisture can still seep into vents and electrical parts. Have it inspected before turning it on. Even a small amount of water can cause corrosion or short circuits over time.