What to Do When Your AC Stops Cooling

18 Jul, 2025 · JUJCO Heating & Cooling

When outdoor temperatures climb across Alberta, an air conditioner blowing warm air can quickly make your home uncomfortable. While some cooling issues are quick homeowner checks, others require prompt professional attention. Here is a practical troubleshooting guide to help you identify what is happening before calling for service.

Check thermostat and power settings

Confirm that your thermostat is set to cooling mode and the temperature is set at least two degrees below the current indoor room temperature. Make sure the fan switch is set to auto rather than continuous on, which can circulate humid air when the outdoor unit is not running. Check your home electrical panel to verify that the air conditioner circuit breaker has not tripped.

Inspect your furnace air filter

A heavily clogged air filter restricts airflow across the indoor cooling coil, causing the system to overheat or freeze up. Check your air filter and replace it immediately if you see heavy dust accumulation. Maintaining clean return airflow is one of the easiest ways to keep your system cooling efficiently.

Check the outdoor condenser unit

Walk outside and inspect the outdoor condenser unit. Ensure the exterior cabinet has at least two feet of clearance from tall grass, shrubs, and windblown debris. If you hear the compressor humming inside the cabinet but the top fan is motionless, turn the thermostat off immediately to prevent electrical motor overheating.

What to do if you see ice

If you notice ice or heavy frost forming along the copper refrigerant lines or across the indoor coil cabinet, shut the system off at the thermostat right away. Continuing to run a frozen air conditioner can permanently damage the compressor. Allow the ice to melt naturally while keeping the system switched off, and call our technicians to locate the underlying airflow restriction or refrigerant leak.

Avoid DIY refrigerant repairs

Refrigerant systems operate under high pressure and require certified diagnostic gauges, digital scales, and specialized licensing to service safely. Adding refrigerant without repairing the source of the leak will not solve the issue and can lead to major component failure.

Call with clear symptoms

Providing specific observations helps our dispatchers diagnose your problem faster. Letting our team know whether the outdoor fan is spinning, whether the indoor blower is running, or if frost is visible on the copper piping ensures our technicians arrive with the correct replacement components on the truck.