Air conditioners tend to fail at the worst possible time, often during the hottest days of summer. Knowing the most common AC problems can help you react quickly and protect your home and family’s comfort.
This article covers frequent issues homeowners see and explains when an inconvenience turns into a true emergency.
1. AC Blowing Warm Air
If your AC is running but the air coming from the vents is warm or only slightly cool, something is wrong. Common causes include low refrigerant levels, a dirty coil, or a problem with the outdoor unit.
You should call a professional if warm air continues after you have checked the thermostat settings and filter.
2. Weak Airflow or Hot/Cold Spots
Weak airflow can make certain rooms uncomfortable and is often a sign of blocked ducts, a failing blower motor, or a dirty filter. Some areas of the home may feel much warmer than others, even when the AC is running.
If basic steps like opening vents and changing the filter do not help, a technician should inspect the system.
3. Strange Noises
Grinding, screeching, banging or rattling sounds usually mean mechanical parts are loose, worn or failing. Ignoring unusual noises can lead to more serious damage and higher repair costs.
Turn off the system and schedule service if you hear anything that does not sound normal.
4. Unusual Smells
Burning, musty or chemical smells coming from your vents should never be ignored. They may indicate electrical issues, overheating parts, or mold growth in the system.
A burning odour or signs of smoke call for immediate shutdown and emergency service.
5. Water Leaks Around the Indoor Unit
Your AC produces condensation, but it should be drained away through a proper line. If you notice water pooling around the indoor unit or stains on ceilings and walls, there may be a clogged drain or another issue.
Water leaks can damage floors, walls and ceilings, so do not wait to have them inspected.
6. Frozen Evaporator Coil
If the indoor coil freezes, you might see ice on the unit or notice your AC running but not cooling properly. This can be caused by low refrigerant, poor airflow or other system problems.
Turning off the system to let the coil thaw is only a temporary step. A technician should find and fix the underlying cause.
7. Sudden Spike in Energy Bills
A sudden increase in your electricity bill, without an obvious change in weather or usage, can indicate your AC is struggling. Causes may include low refrigerant, failing components, or poor maintenance.
A professional inspection can identify the problem and help bring your costs back under control.
When Is It an Emergency?
Some AC problems are inconvenient, but others require urgent attention to avoid damage or health risks. Treat it as an emergency if:
- There is no cooling during extreme heat.
- You smell burning, see smoke, or suspect an electrical problem.
- Water leaks are threatening ceilings, walls or valuable belongings.
- Someone in the home has health conditions that make heat dangerous.
In these situations, turn off the system and call a 24/7 emergency HVAC service right away. Prompt action can protect your home and get your AC back up and running as quickly as possible.