With the AC not cooling, check the thermostat, the air filter and the breakers before anything else, because those three cause a surprising share of calls. If the house still will not cool after that, turn the system off rather than letting it run, and get a licensed HVAC professional to look at it. One Call Home Pros connects you with a vetted, insured local pro who repairs central air systems every day.
The short answer
In Florida, a central air system that stops cooling usually has one of a handful of problems. The airflow is choked by a dirty filter or coil. A safety switch has shut it down because the condensate drain is blocked. A starting part such as a capacitor or contactor has failed in the outdoor unit. Or the system has lost refrigerant through a leak.
Some of these you can spot yourself. Others need gauges, meters and a licence. The checks below are the safe ones.
What to check first
These take about two minutes and need no tools. A good share of calls about an AC not cooling end right here, with a new filter or a reset breaker.
- Set the thermostat to cool, with the set temperature below the room temperature. Replace the batteries if the screen is blank or faint.
- Pull out the air filter and hold it up to a light. If you cannot see light through it, replace it.
- Check the breakers for both the indoor and outdoor units, and the disconnect switch on the wall beside the outdoor unit.
- Go outside while the system is calling for cooling. Check whether the outdoor fan is spinning and the unit is running.
- Look at the copper lines and the indoor unit for ice, and at the floor around the air handler for water.
- Make sure the return grille and the supply vents are open and not blocked by furniture or curtains.
When running it longer makes it worse
It is tempting to leave the system on and hope it catches up. In some cases that turns a small repair into a large one. Switch the cooling off at the thermostat if:
- There is ice on the lines or the coil. Running a frozen system can send liquid refrigerant back to the compressor. Leave the fan on to help it thaw.
- The outdoor unit hums but the fan does not spin. The compressor may be trying to start without its fan, and it overheats quickly.
- A breaker trips again after one reset. The fault is still there.
- You hear grinding, screeching or loud banging from either unit.
- You smell burning near the outdoor unit, the air handler or the vents.
When to stop and call a pro
Some parts of an AC system are not for homeowners. The outdoor unit holds a capacitor that stores a charge even with the power off. The refrigerant lines carry refrigerant under pressure, and handling it legally needs certification. The electrical panels inside both units carry high voltage. Leave all access panels closed, do not touch the service ports on the copper lines, and do not try to add refrigerant.
Why Florida systems fail this way
A system in South Florida runs for most of the year and pulls a great deal of water out of humid air. That heavy use wears the parts that start the outdoor unit, and the moisture feeds algae in the condensate drain line. When the drain backs up, a float switch shuts the system off to protect the ceiling below. The result looks like a dead AC, not cooling at all, even though the cause is a blocked pipe.
Near the coast, salt in the air corrodes outdoor coils and electrical connections faster. Inland, grass clippings, leaves and overgrown shrubs against the outdoor coil restrict airflow. Either way, the system has to work harder to move the same heat out of the house.
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What the pro looks at
An HVAC pro diagnosing a system that will not cool will usually check:
- The capacitor, contactor and wiring in the outdoor unit
- Refrigerant pressures and temperatures, and signs of a leak
- The indoor coil and outdoor coil for dirt and damage
- The blower motor, belt or wheel in the air handler
- The condensate drain, pan and float switch
- The thermostat and its wiring
If refrigerant is low, a good pro looks for the leak rather than only topping it up. Refrigerant does not get used up, so a low charge always means it has gone somewhere.
How One Call fits in
One Call Home Pros is a connector. Florida licenses air conditioning contractors, and the licence belongs to the pro, never to One Call. You tell us what the system is doing and what you have checked, and we match you with a vetted HVAC professional who holds that licence and carries insurance. The pro diagnoses the fault, explains it plainly and makes the repair. One Call arranges the visit and stays with the job.
You pay One Call for the work, and One Call pays the pro. Ask what the price covers before the repair starts. You can read more about AC repair, or see the pages for AC repair in Plantation, Davie and Pompano Beach.
Questions about an AC not cooling
How long should I wait before calling?
If the safe checks have not helped and the house is still warming, call. Do not leave a system running that is iced up or humming without its fan.
Can a dirty filter really stop the cooling?
Yes. A blocked filter cuts the air across the indoor coil. The coil gets too cold, ices over and stops cooling the air.
Why did my AC shut off with water in the pan?
Many systems have a float switch that turns the AC off when the condensate pan fills. A blocked drain line is the usual cause.
Can I add refrigerant myself?
No. Handling refrigerant needs certification, and a low charge means a leak that has to be found. That is work for a licensed pro.
Does One Call repair air conditioners?
No. A licensed, insured HVAC professional from a local company does the repair. One Call vets the pro, arranges the visit and stays with the job.
Get the AC looked at
If the AC not cooling has outlasted the simple checks, switch it off and tell One Call what it is doing. We connect you with a vetted, licensed local HVAC pro.