Your AC system is your cooling hero during the hotter months. Imagine stepping inside to escape the heat, turning it on and feeling hot air blowing through the vents — or no air at all. After sitting idle through the winter, air conditioner problems can creep in. Identifying and solving these issues quickly is your ticket to a cool, comfortable home.
This guide covers a range of common AC issues, from refrigerant leaks to faulty fans. Learn what to look for, tips for troubleshooting air conditioner problems and when to call the professionals.
How to Know if Your Air Conditioner Is Broken
From strange noises to unpleasant smells and uneven temperatures, your AC will tell you when something’s wrong. Common signs of air conditioner problems include:
- Airflow issues: Weak, hot or no airflow can indicate anything from a faulty thermostat to clogged air filters.
- Unusual noises: Banging, hissing, rattling or squealing are your AC’s cries for help. Clanking may mean loose hardware inside the compressor, while hissing warns you of a refrigerant leak.
- Rising energy usage: When your AC works harder than usual, it can cause your energy bills to increase.
- Unpleasant smells: Left unchecked, the causes of foul odors could risk your health and safety. A musty odor could come from mold or mildew growth inside the unit, which can lead to respiratory problems. If you smell rotten eggs, call a professional immediately — there could be a gas leak.
- Imbalanced temperatures: Your air conditioner should keep temperatures even throughout the house. If your bedroom feels like a sauna but your living room is chilly, it’s a sign of AC inefficiency.
- Frequent or constant cycling: Air conditioners run in cycles. They activate, run for a few minutes, then shut off again. Short cycling is when the air conditioner shuts off before the cooling cycle ends. Both short cycling and constant cooling are causes for concern.
Contact your local heating, ventilation and air conditioning (HVAC) service provider if you notice any of these signs. Professional repairs can resolve the issue and boost your air conditioner’s performance.
Why Is Your AC Not Working?
Potential causes of AC malfunctions include leaks, dirty air filters or compressor damage. When problems strike, knowing whether a DIY or professional solution is best can save you time and money and protect your health. Here are the most common AC issues and how to solve them.
1. Refrigerant Leak
Refrigerant is the chemical responsible for cooling in air conditioning and refrigeration systems. It changes temperatures by moving between liquid and gas states, absorbing heat and leaving cool air behind. A refrigerant leak needs immediate action. This type of leak does more than reduce cooling performance — it poses health and environmental risks.
Bubbling or hissing sounds, ice on the refrigerant line or energy bill increases can all point to a leak. Contact a reputable HVAC repair company if you notice any of these signs. AC technicians have the expertise and tools for safe, speedy refrigerant leak repairs.
2. Clogged Condensate Drain Line
Water leaking from your AC unit is a sign that it needs attention. Your AC’s condensate system drains excess moisture. When the drain line becomes blocked or the pump malfunctions, it can cause water to back up and leak out of the unit.
You may be able to clear a clogged condensate drain line yourself. Try the following steps:
- Turn off your AC unit.
- Locate your drain line. You should find it near the outdoor condenser unit or the indoor air handler.
- Remove the drain line’s cap and inspect the line for debris or blockages using a flashlight.
- Remove any clogs using a wire brush or a wet and dry vacuum.
- Flush the line using diluted vinegar to break down any debris. Use water to flush the line again and clear any blockages.
- Clean the drain pan and check for free-flowing water.
If your air conditioner leaks after unclogging the drain line, call an HVAC expert.
3. Frozen Evaporator Coil
Warm air passing over the evaporator coil causes the refrigerant to change from liquid to gas. Dirt buildup can cause the evaporator coil to receive too little air. Without warm air, the refrigerant will freeze the moisture on the coil.
The solution is to thaw and clean the evaporator coil. First, turn off and disconnect your AC unit. You can find the evaporator coil in the air handler for a stand-alone system or attached to your furnace. Inspect the coil for ice formation. For moderate frost, keep your air conditioner fan running to melt the ice or leave it off until the coil thaws. Once thawed, use a vacuum or soft brush to remove any dirt and debris.
4. Malfunctioning Thermostat
Thermostat issues can cause many problems, like short cycling or uneven temperatures. The causes of a faulty thermostat also vary. It could be as simple as dead batteries or a more complex wiring issue.
The solution for a thermostat malfunction depends on the root of the problem. Examine your thermostat to determine the cause and apply one of the following fixes:
- Replace batteries: If you have a battery-operated thermostat, try changing the batteries.
- Adjust settings: Incorrect program settings could be why your AC blows hot air instead of cold. After a power outage, your thermostat may reset to the default manufacturer’s settings. Check the AC mode and time settings, adjusting if needed.
- Reposition the thermostat: Place your thermostat on an interior wall for optimal performance, keeping it away from direct sunlight and drafts.
- Remove dirt buildup: Remove the thermostat’s cover and use a soft brush to remove any dust or dirt. Corrosion inside the thermostat needs professional intervention.
- Bring in an expert: Call a professional for faulty wiring or ongoing thermostat issues. Attempting to fix electrical problems yourself risks your safety and further damage.
5. Dirty Air Filters
The filters inside your AC trap particles like pollen, dust and mold. They stop these pollutants from returning to the air or causing damage to the HVAC system. Blocked air filters affect indoor air quality (IAQ) and reduce AC efficiency.
You can clean reusable air filters by removing them, washing them in water and letting them dry. Follow the filter manufacturer’s guidelines or ask your HVAC contractor for advice on how often to clean the filters. A good practice is cleaning or replacing air filters every one to two months during the cooling seasons. If your AC runs continuously or you have pets, consider changing the filter monthly.
6. Damaged AC Components
With time and frequent use, your air conditioner’s parts can become worn or damaged. Faulty components can cause various issues:
- Compressor failure: A damaged compressor can cause insufficient cooling or weak airflow.
- Capacitator issue: The capacitor starts the AC motor. Extreme heat or power fluctuations can damage this essential part.
- Electrical faults: Tripping circuit breakers or acid buildup can cause electrical failures. Faulty wiring or installation may also cause your air conditioner to fail.
- Bent AC fins: Vents or condenser fins can become bent from debris impact. Bent fins trap warm air inside the unit, reducing efficiency and increasing your energy bills.
Problems with your air conditioner’s components need professional care. HVAC specialists can diagnose the issue and resolve it on the spot. Repairs prevent further damage, saving you money on major overhauls or complete replacements.
Regular maintenance keeps your air conditioner in peak condition. During an AC tuneup service, technicians inspect the system, clean all components and replace air filters or worn parts.
Your Go-To Air Conditioning Experts in Southeastern Wisconsin
Are air conditioner issues making you sweat? Let the experts at Thielmann Heating, Cooling, & Plumbing cool your concerns. Since 1929, customers throughout Southeastern Wisconsin have trusted us with their AC needs. We offer same-day services to restore your home comfort. Our technicians handle everything from expert air conditioning installation to quick and efficient repairs.
Call us or schedule your service appointment online today!
