My AC won't run after a power outage

Check these, in this order

1. Thermostat: is the display on? A blank thermostat usually means it lost its low-voltage supply, not that the whole system is dead.
2. Breakers: look for the air handler breaker and the separate outdoor-unit breaker. A tripped breaker sits slightly off-center — push it fully off, then on. Reset once.
3. The outdoor disconnect: the small box on the wall near the condenser. It can be switched off during storm prep and forgotten.
4. Wait five to ten minutes. Many systems hold the compressor off after a power interruption to protect it.
5. Air filter and condensate switch: a saturated filter or a tripped float switch can keep a system locked out. The float switch is a common one after heavy rain.
6. If the breaker trips again on the second attempt, stop. That is a fault, not a nuisance trip.

Why an outage damages air conditioners

The damage usually happens at the moment power is restored rather than while it is off. Restoration can bring voltage back unevenly, and equipment across the neighborhood tries to start at the same instant. Air conditioners are particularly exposed because the compressor draws a large inrush current and because modern systems depend on a low-voltage control board and a thermostat that are far less tolerant of a spike than the motor is.

Three failures show up repeatedly after South Florida outages: a blown low-voltage fuse on the control board (cheap, quick), a damaged control board or contactor (a parts job), and a compressor that has been stressed by repeated restart attempts (the expensive one). The reason technicians ask homeowners to stop resetting the breaker is that the third failure is often caused by trying to fix the first two by force.

When it is urgent in South Florida

Heat is the risk factor, not the equipment. Extended indoor heat is dangerous for infants, older adults, people with chronic illness and anyone on medication that affects temperature regulation, and CDC guidance on extreme heat treats a hot indoor environment as a health exposure rather than a comfort problem. In a Florida summer, an interior that is not being cooled and not being ventilated climbs quickly, and humidity keeps it uncomfortable overnight.

If someone in the household is vulnerable and the home is not cooling, treat it as urgent: move to a cooler location if you can, keep fluids up, and get the system looked at rather than waiting for a scheduled slot. If anyone shows signs of heat illness — confusion, hot dry skin, fainting — call 911 first.

What a technician will actually check

• Incoming voltage at the disconnect and at the air handler, to confirm the supply itself is sound
• The low-voltage transformer and control-board fuse
• Contactor and capacitor at the outdoor unit — a failed capacitor is a classic 'hums but won't start' cause
• Compressor windings and start behavior, to establish whether damage has already occurred
• Float switch, drain line and filter, which can lock a healthy system out
• Whether a surge protective device is present, and what it did

Preventing the next one

Turning the system off at the thermostat when the power fails, and leaving it off for a few minutes after power returns, avoids asking the compressor to start into the worst possible conditions. Some homeowners also switch the outdoor disconnect off during a named storm. Whole-home or equipment-level surge protection is the other common measure — ask an electrician or HVAC contractor what is appropriate for your panel and equipment rather than relying on a plug strip.