An air conditioner that runs but leaves rooms warm needs attention, especially when the change is sudden.
- Other common signs include weak or uneven airflow, short cycling, a frozen indoor coil, unusual buzzing or grinding, water near the furnace or air handler, unpleasant odours, or a breaker that trips when cooling starts.
- A thermostat that shows a cooling call while the equipment stays quiet can point to a control, power, or equipment issue.

