Your thermostat is set to 68 but the vents are pushing lukewarm or hot air. This one has a handful of causes and most of them don't require a new AC.
You probably came here because…
- The AC compressor outside is running but the inside air feels warm
- You just came home to a hot house even though the thermostat is set low
- The AC ran fine yesterday and today it's blowing warm
- The vents feel warm on the top floor but okay downstairs
What’s actually happening
Four things cause warm air from an AC that's still running: the thermostat got flipped to heat by mistake, the outdoor unit lost power, the refrigerant is low from a leak, or the indoor coil is frozen and thawing.
The thermostat one sounds silly but we see it constantly. Someone bumped it, the batteries died and it reset, or a kid was playing with it. Check that first before you assume the worst.
If the outdoor unit isn't running at all, it's a power issue. Breaker tripped, disconnect got flipped, or the capacitor is dead. If it IS running but you're getting warm air inside, that's refrigerant or airflow.
What we do about it
Check the thermostat
Confirm it's set to Cool, not Heat or Fan. Fresh batteries if it's battery-powered. If the display is blank, that's a wiring or power issue at the thermostat itself.
Look at the outdoor unit
The big metal box outside. Is the fan spinning? If not, that's the problem. Check the breaker in your panel and the disconnect box on the wall next to the unit.
Check the indoor coil for ice
Pull the air filter and look through the return. If you see frost or ice on the coil, shut the AC off for 3-4 hours to let it thaw, then run just the fan. If it re-freezes, call us.
When to just call
If the coil is icing up repeatedly, if you hear hissing near the outdoor unit, or if it's 95 outside and your family is uncomfortable, call (423) 637-1846. Refrigerant leaks won't fix themselves and running the system low destroys the compressor.
Ready to fix it?
Call the family that’s been doing this in the Sequatchie Valley since 1996.