Some people are concerned about what could happen if they left their AC or heat pump running during a rainstorm so they always shut the unit off any time it rains. The truth is that there is no reason you need to shut an outdoor HVAC unit off when it rains as it can keep working without risking any damage. A lightning strike could obviously damage your unit, but this would happen regardless of whether it’s running or shut off. In this article, we’ll discuss the impact that rain, moisture, and weather can potentially have on an AC or heat pump and how to know when it’s an issue.

Can Rain Damage an Outdoor HVAC Unit?

Rain is generally never an issue for an AC condenser or a heat pump as all outdoor HVAC units are designed and manufactured to be completely weather-resistant. All of the internal wiring and electrical components in an AC condenser or heat pump are fully sealed so they are water-tight and shielded from rain and snow. All of the exposed components are also made from durable materials like plastic, aluminum, and copper that are mostly resistant to rust and corrosion. The fact that the electrical components are completely sealed is why there’s no need to shut the unit off when it’s raining. It can continue to run just fine without any issues.

The only time you’d really ever need to worry about the components rusting or corroding is if moisture gets trapped inside the unit and can’t evaporate. This shouldn’t ever happen as long as there is enough clearance around the unit so that air can easily flow through it and allow condensation and moisture to evaporate. However, it can easily occur if you were to cover or wrap the unit with plastic. This is why you should either always leave the unit uncovered or buy a breathable cover made specifically to fit your unit.

To ensure the unit has proper airflow, always keep any nearby vegetation cut back so that there is at least a clear two-foot path around your AC or heat pump. Also, regularly clear leaves and debris away from the unit. This will ensure that air can always easily flow through it, which is important both for preventing moisture buildup and ensuring that the unit can work effectively. If the unit doesn’t have sufficient clearance and airflow, it may start to frequently overheat and could stop working or get severely damaged.

There is one thing to watch out for during heavier or prolonged periods of rain. This is to make sure that all of the water doesn’t start to undercut the pad or base that the AC or heat pump sits on. If this were to happen, it could knock the unit off balance so that it no longer sits level. The unit will still typically work if it isn’t completely level, but it may vibrate much more and make a lot of noise. In rarer situations, the oil may not properly flow through the compressor motor if the unit is too far out of level. This can put the motor at risk of overheating and seizing up.

How Flooding Impacts HVAC Units

The only time you ever need to worry about rain damaging your AC or heat pump is if it rains enough that the area around the unit floods. It could only flood to where there is just a couple of inches of water around the base of the unit for a short time. Then, you usually won’t need to worry about it getting damaged. However, if the water rises high enough that it actually starts flooding the inside of the unit, you should immediately shut the unit off. You can do this by flipping the circuit breaker in your main electrical panel. This will prevent electricity from flowing to the unit to prevent the risk of electrocution.

Once the rain has stopped and your unit is no longer flooded, you should then have a certified HVAC technician perform a full inspection to check for any damage. A technician won’t ever inspect or work on the unit if it is still raining or if the unit is still flooded. This could be extremely dangerous, so you’ll need to wait for all of the water to go away before technicians can work on the unit safely.

Any time an AC or heat pump is exposed to flooding, there is a high chance that some of the internal components will be damaged. If you try to run the unit before having it inspected and it is damaged, you will likely make the damage worse and could ruin the unit entirely. The electrical components and wiring are the parts that are most likely to suffer damage when exposed to water. This could lead to a short circuit that could burn out the compressor and fan motors if you were to turn the unit on.

The unit’s fan motor can be replaced or repaired quite easily, but technicians can’t repair a compressor motor. They can replace the compressor motor, however, though this is prohibitively expensive. It will typically cost about the same price as simply buying a new AC or heat pump.

As long as you don’t try to run your unit while it is still flooded or before having it inspected, the damage caused by the flooding will often be repairable. At least some of the electrical components will usually have to be replaced. Technicians may also need to replace any components that have rusted or corroded.

How Hail and High Winds Can Affect Outdoor HVAC Units

Severe storms that produce large hail or extremely strong winds can potentially affect your AC or heat pump. As such, it’s always a good idea to go outside after the storm ends and perform a quick visual inspection of the unit. You’ll want to make sure that there aren’t any sticks or twigs stuck in the top of the unit that could prevent the fan from spinning. If the storm blew lots of leaves and debris inside the unit, you may want to have a technician clean everything out. This is because the leaves can retain lots of moisture, which could again lead to rust and corrosion.

Hail is more likely to cause cosmetic damage as it could easily dent the unit’s outer casing. Still, this isn’t anything to worry about since it won’t have any effect on the unit’s performance. However, there is a risk of large hailstones damaging or bending the unit’s fan blades or harming the fan motor.

If any of the fan blades are bent or dented, they’ll throw the fan out of balance and cause it to wobble, shake, and vibrate as it runs. This can damage the unit over time or cause the fan motor to wear out more quickly. So it’s a good idea to have the fan replaced if the blades are damaged. A blade that is cracked or severely bent could prevent the fan from spinning. This will typically lead to the fan motor quickly overheating and the unit then automatically shutting off.

Southland Heating & Air Conditioning is a top choice if you need any air conditioning or heating repairs in Newbury Park. We repair, service, and install all types of HVAC units including central and ductless ACs, heat pumps, and furnaces. We also service whole-house fans, air purifiers, and other indoor air quality units. Give us a call today if you have any questions about your home’s HVAC system or to schedule a service appointment.

company icon