Run this checklist. In order.
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Thermostat. Set it to COOL, not OFF, not HEAT, not FAN. Drop the setpoint five degrees. Blank or dim screen? Replace the batteries.
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Breaker panel. Find the breaker labeled AC, air handler, or condenser sitting between ON and OFF. Push it fully to OFF, then firmly to ON.
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If it trips a second time, stop. Leave it OFF. Call a licensed pro.
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Float switch. Check the indoor air handler for standing water in the drain pan or on the floor. A clogged drain trips a safety switch that kills the system. The most common cause in Florida.
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Air filter. Pull it. If light does not pass through, replace it.
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Outdoor unit. Is the fan spinning? Check the gray disconnect box beside it.
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Ice. Frost on the copper lines? Thermostat to OFF, fan to ON. Let it thaw.
1. The thermostat
Dead batteries are easy to miss, because some models keep a faint display while losing the power to close the cooling relay. A dark screen on a hardwired thermostat points to a blown low voltage fuse or a tripped float switch.
2. Breakers, and the rule that matters
Push the handle all the way to OFF first, since most breakers will not reset from the middle position. Then firmly to ON. Dry hands, dry footing, one hand.
Here is the part people skip. If it trips again, you are done. One reset is troubleshooting. A second is asking a damaged circuit to fail while you stand in front of it. Repeat tripping means a short, a failing compressor, or bad wiring.
Do not reset at all if you smell burning plastic, see scorch marks, or hear buzzing. Never open the panel.
3. The float switch, and why Florida units quit at night
This is the one. Your coil pulls a remarkable amount of water out of Central Florida air. It drains into a pan and out a PVC line, usually 3/4 inch, that exits outside near the foundation.
Algae grows in it all summer. When it clogs, the pan fills, and a condensate overflow float switch cuts the system off on purpose to keep water out of your ceiling. Your AC did not break. It protected the house.
The clue is water: a wet pan, a damp floor, a stained ceiling.
What you can safely try, with the system OFF at the thermostat:
- At the air handler, find the short vertical PVC stub with a removable cap, often near a tee fitting. That is your access point.
- Put a wet/dry shop vac on the outdoor end of the drain line. Seal around the pipe with a rag and run it two minutes. Clogs come out as black sludge.
- Pour a cup of white vinegar into the indoor access port.
When not to: if the air handler sits in a hot attic, wait for daylight. If you cannot find the cap, do not cut PVC. If water reached drywall, call.
4. Filter
A filter clogged solid starves the coil, causing weak cooling, freezing, and sometimes a shutdown. Check one inch filters monthly here, which is the job of a preventative maintenance plan.
5. Outdoor unit not running
Indoor fan blows, outdoor unit silent: check the gray disconnect box for a loose or missing pull-out block. A humming unit with a still fan usually means a failed capacitor or contactor.
Outdoor fan spins, house stays warm: the compressor is down, or the charge is low.
6. Ice on the lines
Ice on the suction line or coil means too little airflow or refrigerant. Do not chip at it. Set the thermostat to OFF and the fan to ON. Warm air melts it, generally in three to four hours. Put towels down. Change the filter, then try cooling. Ices again? Call.
7. Blowing but not cooling, versus not blowing at all
Air moving but warm: the blower has power, so the cooling side failed. Capacitor, contactor, compressor, leak, or no power outdoors.
No air at all: the blower is down. Power, thermostat, float switch, control board, or motor. Tell us which one you have.
Safe for you, and not
Safe: thermostat, batteries, filter, one breaker reset, the disconnect, clearing a condensate line, thawing a coil.
Not safe:
- Refrigerant. EPA rules under Section 608 of the Clean Air Act restrict refrigerant sales and service to certified technicians. There is no consumer top-off. If it is low, it leaked, and the leak has to be repaired.
- Capacitors. They store an electrical charge and can hold it after the power is off. Touching the terminals can injure or kill you. Stay out of the outdoor unit’s panel.
What to tell us on the phone
Outdoor unit running, humming, or silent? Air from the vents, warm or cool? Water around the indoor unit? Did a breaker trip twice? Ice on the lines? Brand, age, and where the indoor unit sits. That decides what parts ride on the truck.
Honest note on after-hours pricing
Emergency rates are normal. Someone is being pulled out of bed. Ask three things before you agree: what is the after-hours diagnostic fee, does it apply toward the repair, and do you get a price before work starts.
Staying safe until morning
An Orlando house does not cool off overnight, and humidity is what makes Florida heat dangerous.
- Move air. Box fans in windows, ceiling fans on, doors open. Fans help below 90F indoors. Above that, moving hot air across skin can raise body temperature, so a fan does not replace getting somewhere cool.
- Drink water steadily. Skip alcohol and heavy caffeine.
- Shrink the space. Close unused rooms, sleep in the lowest shaded room.
- Cool the body, not the house. Cool shower, damp towels on the neck.
Who should not wait it out: infants, adults 65 and older, pregnant women, anyone with heart disease, asthma or another chronic condition, and anyone on medications affecting hydration or temperature regulation (blood pressure drugs, diuretics, antihistamines, some psychiatric medications). Go somewhere cool now: a relative’s, a hotel, a cooling center.
Heavy sweating, clammy skin, weakness, dizziness, or nausea point to heat exhaustion. Get cool, sip water, seek care if it lasts over an hour. Confusion, slurred speech, hot skin, or loss of consciousness point to heat stroke. Call 911.
FAQ
Why does my AC shut off at night but work fine during the day?
Usually a clogged condensate drain. Long overnight runtime fills the pan until the float switch cuts power. By morning the water level drops and the system restarts, so the failure looks intermittent. A weak capacitor struggling in heat does the same.
Is it safe to reset a tripped AC breaker myself?
Once, yes, if there is no burning smell, no scorch marks, and no buzzing. Push the handle fully to OFF, then firmly to ON, dry hands and dry footing. If it trips again, leave it OFF and call a pro.
Can I clear my own AC drain line?
Often yes. Shut the system off, find the capped PVC access near the air handler, and put a wet/dry vac on the outdoor end of the line to pull the clog out. Follow with a cup of vinegar. Skip it if water reached drywall.
Why is my AC blowing air but not cooling?
The blower has power, but the cooling side failed. Common causes are a bad run capacitor, a failed contactor, a tripped compressor, a refrigerant leak, or no power at the outdoor unit. Check the disconnect. Everything past that needs a tech.
How long does a frozen AC coil take to thaw?
Usually three to four hours with the thermostat OFF and the fan set to ON, longer for heavy ice. Never chip at it. Put towels down for the melt water, then change the filter before restarting. If it freezes again, get it diagnosed.
Still hot? We answer at 2am.
Airborne Tech Service is a family owned HVAC and commercial refrigeration company, licensed as a Certified Air Conditioning Contractor, CAC1822084. We run 24/7 emergency AC repair in Orlando, Winter Park, Maitland, Altamonte Springs, Casselberry, Winter Springs, Longwood, Oviedo, Lake Mary, Sanford, Apopka, Kissimmee, and Deltona.
Call (321) 240-9346.
Not an emergency? Contact Airborne Tech Service about maintenance, see AC service in Orlando, or review AC installation options.