Emergency AC Checklist for Killeen Homeowners

Step 1 — Confirm the system is being told to cool

• Thermostat set to cool, not auto or off.
• Setpoint at least a few degrees below the current room temperature.
• Fan set to auto so you can tell whether cooling is engaging.
• Fresh batteries in a battery-powered thermostat.
• No schedule, hold or app override working against you.

Step 2 — Check power, once

• Look at the breakers for the indoor and outdoor equipment.
• Reset a tripped breaker one time only.
• If it trips again, stop — that repetition is a symptom, not a nuisance.
• Confirm the indoor unit's service switch has not been flipped off.

Step 3 — Look for water and ice

• Check for standing water in or under the indoor unit.
• Look for a ceiling stain under attic-mounted equipment.
• Check whether a condensate float switch has interrupted operation.
• Look for frost or ice on the refrigerant lines or coil.
• If frozen: turn cooling off, set fan to on, and let it thaw.

Step 4 — Check airflow basics

• Replace the filter if it is safely accessible and dirty.
• Open closed supply registers.
• Clear furniture, rugs or boxes away from return grilles.

Step 5 — Stop and shut down if you see any of these

In these situations, turn the system off at the thermostat and, if it can be done safely, at the breaker, then seek qualified assistance. Never open high-voltage HVAC components, discharge capacitors, bypass safety switches or attempt anything involving refrigerant.

• Smoke, sparking or visible electrical arcing.
• A burning or hot-electrical smell.
• Water reaching electrical components or a light fixture.
• A breaker that trips again immediately after one reset.

Step 6 — Make the call productive

• When the problem started and whether anything changed just before.
• Whether the indoor blower runs and whether the outdoor unit runs.
• Whether vent air is cool, neutral or warm, and how strong the airflow is.
• Current indoor temperature versus setpoint.
• Any ice, water, smells or unusual sounds.
• Whether you reset a breaker or changed the filter.

Staying tolerable while you wait

• Close blinds and curtains on sun-facing windows.
• Run ceiling and box fans to keep air moving.
• Keep interior doors open so air can circulate.
• Avoid the oven, dryer and other heat sources.
• Drink water and check on anyone sensitive to heat.