7 Signs Your Air Conditioner Needs Repair

This is the most obvious sign something is wrong. If your AC is running but blowing warm or room-temperature air, you likely have one of three issues: a refrigerant leak, a failing compressor, or a problem with the condenser unit. None of these are DIY fixes. Low refrigerant, in particular, is a regulated substance in Canada and must be handled by a certified HVAC technician.

  What to do: Check your thermostat first, make sure it’s set to “cool” and the fan is set to “auto,” not “on.” If settings are correct and warm air persists, call an air conditioner repair technician.

Poor airflow usually means your system is struggling to push air through the ductwork. Common culprits include a clogged air filter, a failing blower motor, or leaky/blocked ducts. In commercial buildings, weak airflow across multiple zones can signal a more serious system-wide issue.

  What to do: Start by replacing your air filter — this is the one maintenance task you can do yourself. If that doesn’t solve the problem, it’s time for a professional inspection.

Your AC should run in fairly consistent cycles, especially on hot Calgary days. If you notice it turning on and off every few minutes, that’s called short cycling — and it’s a red flag. Short cycling puts tremendous strain on your compressor, driving up energy bills and shortening the life of your system. It can be caused by an oversized unit, a dirty condenser, low refrigerant, or electrical issues.

  What to do: Don’t ignore this one. Short cycling accelerates wear and can turn a repairable problem into a full replacement. Get it diagnosed early.

Your air conditioner should run relatively quietly. Unusual sounds are your system’s way of asking for help:

• • • Banging or clanking — a loose or broken component inside the unit
    • Grinding — worn motor bearings
    • Squealing — a slipping belt or motor issue
    • Hissing — possible refrigerant leak

Any of these sounds warrant a call to an HVAC professional. Operating the system while it’s making grinding or banging sounds can cause additional damage.

A small amount of condensation around your AC unit is normal. But pooling water or visible ice on the coils or refrigerant lines is not. Ice buildup usually means restricted airflow or low refrigerant, and if left alone, it can cause compressor damage — one of the most expensive AC repairs possible.

  What to do: Turn the system off and let it thaw. Then call an HVAC technician before turning it back on. Running a frozen system makes things worse.

If your electricity bills are climbing but your usage habits haven’t changed, your air conditioner may be working harder than it should. An inefficient system — due to dirty coils, low refrigerant, or aging components — has to run longer to achieve the same cooling, burning more energy in the process. This is especially relevant in Calgary, where both residential homeowners and commercial building managers watch operational costs closely.