Reset a tripped AC breaker, and what not to touch
When the AC goes silent, a tripped breaker is a fair first check. One reset is fine. A breaker that trips again is telling you to stop.
What to watch for: His demo board is a general panel, not an AC. The reset is the same. The difference for your AC: if it trips again, stop there and call.
Why does this matter in Tucson?
Central AC usually runs on a double-pole breaker, two handles tied together, labeled AC, condenser or heat pump. A trip cuts power to protect the wiring. Sometimes that happens once after a monsoon power flicker. A breaker that trips again is a symptom of a fault, not the fault itself.
What you'll learn
- How to spot a tripped breaker (it sits in the middle, not on or off)
- Why you push it fully off before turning it back on
- The one-reset rule, and what a second trip usually means
- The parts inside an AC that are a pro's job, even with the power off
How do you do it, step by step?
- Set the thermostat to Off.
- At the main panel, find the AC breaker. A tripped handle rests in the middle position.
- Push the handle firmly all the way to Off until it clicks, then back to On. Both handles of a double-pole breaker move together.
- Wait a few minutes before you ask for cooling. Many outdoor units have a built-in delay before the compressor restarts.
- Set the thermostat back to Cool. Check that the outdoor fan spins and that the air from the vents turns cool.
- Also check the service switch near the indoor unit (it looks like a light switch) and the thermostat batteries if the screen is blank.
When should you stop and call a pro?
- The breaker trips a second time, right away or after a few minutes. Leave it off and call.
- You smell burning, see scorch marks, or hear buzzing at the panel or the outdoor unit.
- The outdoor unit hums but the fan does not turn.
Don't open the outdoor unit's service panel. The capacitor inside can hold a charge after the power is off, and the contactor and wiring carry full line voltage. Don't replace breakers, and don't add refrigerant. Refrigerant work requires an EPA Section 608 certified technician.
Read next
Sources and official pages
Rather have a pro handle it?
Climate Pros Tucson matches homeowners with licensed local HVAC pros across the Tucson area. You talk to us, then to the pro, and the pro quotes the job before any work starts.
What else can you check yourself?
Heat pump defrost: what is normal on a cold morning
Steam rising off the outdoor unit on a cold morning looks alarming. Usually it is the heat pump clearing its own frost, right on schedule.
Monsoon prep for your AC: storms, surges and dust
The monsoon brings the heat and the humidity together, then adds dust, lightning and power flickers. A little prep keeps the AC out of the storm’s way.
Swamp cooler spring start-up and pad change
An evaporative cooler sat dry all winter. Fresh pads, a clean pan and clear water lines get it ready for the dry heat of spring.