It’s the hottest day of the summer here in the GTA, and you notice your home is getting warmer and warmer, even though the air conditioner is running. You put your hand to the vent, and the air coming out is lukewarm at best. It’s a frustrating problem, but don’t panic!

In most cases, an AC that isn’t cooling properly is caused by one of a few common issues. Let’s walk through the three most frequent reasons and what you can do about them.

Reason #1: A Clogged Air Filter

This is the single most common cause of cooling problems, and luckily, it’s the easiest to fix.

• Why it happens: Your air filter’s job is to trap dust, pet dander, and other debris before it enters your HVAC system. Over time, it gets clogged. A clogged filter severely restricts airflow, meaning your AC can’t pull in enough warm air to cool down. In serious cases, this can cause the indoor evaporator coil to freeze into a block of ice, stopping cool air entirely.

• What to do about it:

  1. Turn your air conditioner off at the thermostat.

  2. Locate the filter compartment on your indoor furnace/air handler unit. It’s usually a small slot or door.

  3. Slide out the old, dirty filter. Note the size printed on its cardboard frame.

  4. Slide in a new, clean filter of the same size, making sure the airflow arrows on the filter point towards the furnace.

  5. Turn your system back on.

Pro Tip: You should check your filter every month and plan to replace it every 1-3 months, depending on your filter type and if you have pets or allergies.

Reason #2: A Dirty Outdoor Unit (Condenser)

Your AC system has two parts: an indoor unit and an outdoor unit. The outdoor unit’s job is to release all the heat it has removed from your home.

• Why it happens: The outdoor unit can get covered in dirt, grass clippings, falling leaves, and cottonwood fluff. When the metal fins are caked in debris, the unit can’t “exhale” heat effectively. It will run and run, trying to cool your home, but it will struggle to keep up.

• What to do about it:

  1. SAFETY FIRST: Turn off the power to your outdoor unit. There is a shut-off switch in a metal box on the wall near the unit. For extra safety, turn off the AC breaker in your main electrical panel.

  2. Clear away any leaves, weeds, and branches from around the unit. Ensure there are at least two feet of clear space on all sides.

  3. Using a regular garden hose (NEVER a pressure washer), gently spray down the outside of the unit’s fins to wash away the built-up dirt and debris.

  4. Wait for it to dry completely, then restore power.

Reason #3: Low Refrigerant (A Leak)

If the filter is clean and the outdoor unit is clear, the problem might be more serious.

• Why it happens: Refrigerant is the substance that circulates through your AC, absorbing heat from inside and releasing it outside. Your AC is a closed system, so you should never “run out” of refrigerant. If it’s low, it means there is a leak somewhere in the lines.

• What to do about it:

  1. This is not a DIY job. Simply adding more refrigerant without fixing the leak is a temporary, costly, and environmentally irresponsible fix. The problem will just come back.

  2. Call a licensed professional. A TSSA-certified technician has the proper tools to locate the leak, repair it safely, and then recharge the system with the exact right amount of refrigerant.

Don’t Sweat It—We’re Here to Help

Some AC issues are a simple fix, like changing a filter. Others require an expert hand to diagnose and repair safely.

If you’ve tried these simple steps and your home still isn’t cooling down, the experts at Kamboj Heating & Cooling are ready to help. Contact us today for a fast diagnosis and reliable repair to get your home cool and comfortable again.