Can Rain Damage My HVAC System? A Phoenix Tech Answers

In Phoenix, we rarely get rain, so you may be wondering if the water can damage your outdoor HVAC unit.

The short answer is no, rain should not damage your system.

However, rainstorms may cause other issues that can harm your outdoor unit, such as:

• Flooding
• Storm debris
• Lightning

Below, we’ll look at a few ways that water and storms can negatively impact your HVAC system and what to do to prevent or mitigate damage to your outdoor unit.

As we mentioned above, light to normal rainfall should not damage your system. Why?

The components of your outdoor unit are built to withstand water and are made from materials that are generally corrosion resistant, like:

• Plastic
• Aluminum
• Copper

In addition, the important parts of your outdoor unit (including the electrical connections) are sealed...which means that your system should be able to withstand a decent amount of rain and still work perfectly fine.

However, just because your outdoor unit is generally rain-resistant doesn’t mean it’s completely storm or flood-resistant. Let’s look at a few ways storms can damage your system...

While rain shouldn’t damage your outdoor AC or heat pump unit, flooding or standing water can.

A small amount of water pooling around the bottom of your outdoor unit shouldn’t affect your system, but if water reaches a foot or higher, it can damage the internal parts of your system, like the motor.

If you notice flooding (a foot or higher of standing water) around or under your outdoor unit, you should:

1. Turn off your AC or heat pump
2. Try to get rid of as much standing water as possible.
3. Let your air conditioner dry out
4. Have an HVAC technician come and ensure that nothing is damaged before turning your AC or heat pump back on.

Note: If the downpour is significant enough for flooding, you do not want to cover your AC or heat pump with a tarp. While you may think you’re protecting your system, a tarp can actually trap a lot of moisture in and may not allow the outdoor unit to dry out properly.

The kind of storms we usually get in Arizona (Monsoons) involve a lot of wind, which means all kinds of debris are flying through the air and potentially making their way into your outdoor unit.

Even if debris is small, it can severely damage the internal components of your AC or heat pump, like your outdoor unit’s fan or blower motor.

To reduce the chances of debris damaging your system, you should:

1. Make sure there are no trees/shrubs directly over or within a 2-foot radius of your outdoor unit.
2. Cover your compressor with a PVC-coated polyester mesh screen to prevent debris from falling into your compressor.

If you notice that debris has made its way into the outdoor unit or you hear any loud banging or clicking noises coming from your outside unit, you should immediately turn off your system and reach out to a technician.

A tech will be able to take a look at your system and hopefully remove debris before it severely damages your AC or heat pump. If there is already damage, a tech will be able to help you determine what repairs or replacements will need to be made.

During a thunderstorm, lightning can cause a power surge that could damage or completely ruin your outdoor unit.

While you may think turning off your system will protect it from a power surge, simply turning off the system will not disconnect it from the main circuit of your home.

To protect your HVAC system from damage, your best course of action is to install a surge protector. The surge protector will “protect” your system from any spikes/surges in voltage. If the surge protector notices a surge or spike, it will divert the extra voltage into the ground wire, keeping your system from becoming damaged.

However, if you don’t have a surge protector and your system becomes damaged because of a power surge, you should reach out to a technician for help immediately.

Whether you’ve recently noticed flooding, damage or just want to ensure that your AC or heat pump is working correctly, we’d be happy to take a look. If you think your system is damaged, you can schedule a repair with us.

If your system isn’t damaged but you just want peace of mind that everything is working properly, you should schedule an AC tune-up.

During a tune-up, an experienced tech can take a look at your system and ensure that all parts are working correctly. They will also ensure that your system is set up for success in case heavy winds and rains do end up coming your way.