Heat Waves and Your Home's AC

During a heat wave, your air conditioner may run almost nonstop for days. That is exactly when weak parts tend to fail and when HVAC contractors are busiest. A little preparation helps your system handle the strain and keeps you more comfortable while it works.

Why heat waves are hard on AC systems

Most residential systems are sized to handle typical hot days in your area, not the most extreme ones. When outdoor temperatures climb past what the system was designed for, it may run constantly and still struggle to keep up.

Long run times add stress to the compressor, capacitors, fan motors and contactor. Electrical parts that were already weak often fail first. Dirty coils and low refrigerant make the problem worse.

Prepare before the heat arrives

A few steps in spring or early summer can make a big difference:

1. Replace the air filter. A clogged filter restricts airflow and makes the system work harder.
2. Clean around the outdoor unit. Clear leaves, grass and debris. Trim plants back so air can flow freely around the condenser.
3. Rinse the condenser coil gently with a garden hose (power off first) if it looks dirty. Do not use a pressure washer.
4. Check the condensate drain. A clogged line can shut the system down or cause water damage.
5. Schedule a tune-up. A technician can check refrigerant levels, electrical parts, and coil condition before peak season.
6. Test the system on a warm day before the first heat wave, so you have time to schedule repairs.

Help your AC during a heat wave

You can reduce the load on your system:

• Set a steady, reasonable temperature. Big setbacks during the day can leave the system unable to catch up in the late afternoon.
• Close blinds and curtains on sun-facing windows.
• Use ceiling fans to feel cooler at a slightly higher thermostat setting. Make sure they spin in the summer direction.
• Avoid using the oven and dryer during the hottest part of the day.
• Keep doors and windows closed while the AC runs.
• Make sure supply and return vents are not blocked by furniture or rugs.

Warning signs of trouble

Call for service if you notice:

• Warm air from the vents
• The outdoor unit fan not spinning while the system runs
• Ice on refrigerant lines or the indoor coil
• Buzzing, clicking or grinding noises
• Water pooling near the indoor unit
• The system turning on and off rapidly
• A tripped breaker that trips again after reset

If you see ice, turn the system off and run only the fan to help it thaw, then call a technician. Running a frozen system can damage the compressor.

Keep an eye on the outdoor unit

During extreme heat, glance at the outdoor unit once a day. Make sure the fan is spinning, nothing has blown against the coil, and the unit is not making new noises. Some homeowners shade the area around the condenser, which is fine as long as airflow around and above the unit stays completely clear.

If your AC fails

Heat waves are when repair companies are busiest, so expect delays. While you wait:

• Move to the coolest room, often the lowest level of the home.
• Use fans and stay hydrated.
• Check on older relatives, neighbors and pets.
• Know where local cooling centers are in case you need one.

Heat can be dangerous, especially for older adults, young children and people with health conditions. If the indoor temperature becomes unsafe, seek a cooler place.

Coverage for AC breakdowns

Many home warranty plans cover air conditioning systems for breakdowns from normal wear. Coverage often includes compressors, capacitors, fan motors and thermostats, with exclusions for things like improper maintenance, refrigerant above a set limit, or code upgrades. Ductwork may be separate. Ask how a plan handles urgent service during extreme heat and what its response time goals are.

How Warranty Wizards can help

Warranty Wizards helps you compare home warranty plans from third-party providers and explains what each covers for your AC before you buy. You can request a free quote for your home.