If your HVAC system fails during a heatwave, check the thermostat, reset the circuit breaker, and replace the air filter. Stay cool with fans, block sunlight, and hydrate while waiting for professional repairs.
If your AC suddenly stops working, don’t panic. There are steps you can take to troubleshoot the issue, stay cool while waiting for repairs, and prevent future breakdowns. Understanding why HVAC systems fail during extreme heat can also help you prepare ahead of time.
Why HVAC Systems Fail During a Heatwave
During a heatwave, your HVAC system works harder than usual to keep up with the rising temperatures. This extra strain can lead to system failures if the unit is not properly maintained or if it is already operating at full capacity.
Common Causes of HVAC Failure in Extreme Heat
Overworked System
- HVAC units are designed to run in cycles, but during extreme heat, they often run continuously.
- This can overheat the compressor, leading to a shutdown.
- Older systems may struggle to maintain cooling, especially if they haven’t been serviced recently.
Dirty or Clogged Air Filters
- A dirty filter blocks airflow, causing the system to work harder.
- Over time, restricted airflow can lead to overheating and potential system failure.
- Experts recommend changing air filters every 1-3 months, especially during peak summer months.
Low Refrigerant Levels
- Refrigerant is essential for cooling, and a leak or low levels can cause the system to blow warm air or shut down.
- Signs of low refrigerant include hissing noises, ice buildup, and reduced cooling performance.
Electrical Issues or Tripped Circuit Breakers
- Heatwaves can cause power surges, which may trip your AC breaker.
- Loose or faulty wiring can also cause intermittent system failures.
- If your breaker keeps tripping, call an HVAC professional to diagnose the issue.
Frozen Evaporator Coils
- If airflow is restricted or refrigerant levels are low, evaporator coils can freeze.
- When this happens, the system may stop cooling or shut off entirely.
- The best solution is to turn off the AC, let the ice thaw, and inspect for clogged filters.
What to Do Immediately If Your AC Stops Working
If your HVAC system fails during a heatwave, taking quick action can help prevent further damage and keep your home as cool as possible.
Check the Thermostat
- Make sure the thermostat is set to “cool” and at the desired temperature.
- Check for low battery warnings if your thermostat is battery-powered.
- If your thermostat is unresponsive, try resetting it.
Inspect the Circuit Breaker
- Locate your electrical panel and check if the breaker for the AC unit has tripped.
- If tripped, reset it once, but if it trips again, contact a professional to inspect for electrical issues.
Replace or Clean the Air Filter
- If the air filter is dirty, replace it immediately to restore proper airflow.
- Clogged filters force the system to overwork, leading to overheating and shutdowns.
Check for Ice Buildup on the Unit
- If you see ice on the evaporator coils, turn off the AC and let it thaw.
- While waiting, use fans to circulate air and prevent overheating indoors.
Inspect Outdoor Unit for Debris
- Leaves, dirt, and debris around the outdoor condenser can block airflow.
- Clear any obstructions and ensure at least 2 feet of space around the unit.
How to Stay Cool While Waiting for Repairs
While waiting for an HVAC technician, you can take steps to stay cool and comfortable indoors.
Use Fans Strategically
- Place box fans near windows to push hot air outside.
- Use ceiling fans to circulate air, but set them to rotate counterclockwise to create a cooling effect.
Block Out Sunlight
- Close curtains, blinds, or blackout shades to keep the heat out.
- Reflective window covers can reduce indoor temperatures significantly.
Stay Hydrated and Avoid Heat-Generating Activities
- Drink plenty of cold water and avoid caffeinated or alcoholic drinks, which cause dehydration.
- Avoid using stoves, ovens, or dryers, as they add heat to your home.
Cool Your Body, Not Just the Room
- Use cold compresses on your wrists, neck, and forehead to cool down quickly.
- Take a cool shower or dampen a washcloth and place it on your skin.
Create a Cool Room
- If possible, set up a single room as a cooling zone with fans and damp towels.
- Close off unused rooms to trap cool air where you need it most.
Consider Alternative Cooling Methods
- If the heat is unbearable, go to a public place like a library, shopping mall, or cooling center.
- Portable AC units can provide temporary relief in one area of the home.
How to Prevent HVAC Failures During Heatwaves
Preventive maintenance is the best way to avoid system breakdowns during extreme weather.
Schedule Regular HVAC Maintenance
- Have a professional inspect your system twice a year, ideally before summer and winter.
- Routine maintenance includes:
- Cleaning evaporator and condenser coils
- Checking refrigerant levels
- Inspecting and tightening electrical connections
Upgrade to an Energy-Efficient Unit
- If your AC is over 10-15 years old, consider replacing it with a modern, energy-efficient system.
- Newer models cool more effectively while using less energy, reducing strain during heatwaves.
Install a Smart Thermostat
- Smart thermostats adjust temperature settings automatically, preventing unnecessary strain on your HVAC system.
- They help reduce wear and tear while maintaining optimal comfort.
Ensure Proper Insulation
- Well-insulated homes retain cool air longer, reducing the workload on your AC.
- Insulation should be checked in the attic, walls, and around ductwork.
Keep the Outdoor Unit Clean
- Regularly clear debris, leaves, and dirt from the outdoor condenser.
- Ensure at least two feet of clearance around the unit for proper airflow.
Final Thoughts
A failing HVAC system during a heatwave can be frustrating and dangerous, but knowing how to troubleshoot and stay cool can make all the difference.
By following preventive maintenance tips, keeping filters clean, and upgrading your thermostat, you can reduce the risk of future breakdowns and keep your home comfortable even in extreme temperatures. If your system continues to have issues, it may be time to consult an HVAC professional for repairs or an upgrade.
