Air Conditioner Not Cooling
Five quick checks to try first, the signs that mean you should stop and call, and what to do while you wait.
When the house warms up on a summer afternoon, a few simple checks can tell you whether the fix is a setting, a switch or a filter, or whether the system needs a technician. Go through them in order. None of them needs tools or opening a panel, and if anything on the stop-and-call list below applies, skip straight to calling us at (469) 398-8711.
Have You Noticed Any of These?
Tick what you can see at your system, then press the button for what it usually means and what to try.
AC Troubleshooter
Tick what you have noticed, then press the button.
The Five Checks
- Thermostat: set to Cool, a few degrees below the room, with the fan on Auto. Replace the batteries if the screen is blank or dim.
- Breaker: look for a tripped breaker for the outdoor unit and for the furnace or air handler, and check the disconnect switch on the wall by the outdoor unit.
- Filter: a clogged filter starves the coil of air and can make it freeze. Replace it if it is gray.
- Outdoor unit: with the system calling for cooling, the top fan should spin and the unit should hum steadily. Clear leaves and clippings from the sides.
- Ice on the lines: frost on the larger copper line or on the indoor coil means turning the cooling off and the fan on until it melts.
Stop and Call
Switch the system off at the thermostat and call us if you notice any of these:
- A burning smell, or smoke from a vent or either unit
- Sparking, crackling or a scorched look at the outdoor disconnect or the wiring
- Water pooled near the furnace, air handler or any electrical parts
- A breaker that trips again after one reset
Details to Have Ready When You Contact Us
- What the system is doing, and when it started
- What you have already checked from the list above
- Where the indoor unit is (closet, garage or attic) and how to reach it
- The make and age of the system if you know them, or a photo of the outdoor unit’s label
- Anyone in the house who is especially affected by the heat
Get on the Schedule Call (469) 398-8711
While You Wait
How do I keep the house safe in the heat while I wait?
Close blinds and curtains on the sunny side, keep doors to unused rooms closed, and run ceiling fans. Move to the lowest floor, drink water, and check on older relatives, babies and pets, who feel the heat first. If the indoor temperature climbs past the mid-80s and someone is vulnerable, consider a cooler place to stay until the repair.
My coil is frozen. What should I do?
Set the thermostat to Off and the fan to On. The moving air thaws the coil in a few hours; put towels around the indoor unit for the meltwater. Do not chip at the ice. Once it has thawed, change the filter if it is dirty, but if the coil freezes again it points to a low charge or an airflow problem that needs a technician.
Should I run the fan with the cooling off?
Yes, if the coil is frozen, because the fan thaws it. Otherwise the fan alone only moves warm air around, though it still helps a little with ceiling fans running. If the outdoor fan is not spinning, keep the cooling off: the compressor can overheat without it.
Is it safe to reset a tripped breaker?
Once, yes. If it trips again, leave it off and call. A breaker that keeps tripping is protecting a shorted motor, a failing capacitor or a wiring fault, and resetting it repeatedly can do more damage.