There’s nothing more frustrating than turning on your AC on a hot Utah afternoon and feeling warm air come out of the vents.
Start at the thermostat.
Make sure it’s set to COOL, not HEAT or FAN ONLY. It happens more than you’d think — especially after a chilly Northern Utah night when someone switched it over and forgot to switch it back. Our temperature swings are dramatic. Nights in the 50s and days pushing 95 aren’t unusual.
Check the filter.
A restricted filter reduces airflow so severely the system can’t function properly. In our desert climate, a dirty filter is almost always somewhere in the chain of problems. Check it first, every time.
The outdoor unit needs airflow too.
Go outside and look at your condenser. Is it packed with cottonwood? We get hammered with cottonwood fluff every spring along the Wasatch Front, and it will plug up the outside of your condenser coil like a blanket. You can gently rinse it off with a garden hose — spray from the inside out if you can — but be gentle.
Is the compressor actually running?
Here’s a field trick: find the two copper lines going into your outdoor unit. Grab the larger, insulated one. If your system is cooling properly, that line should feel cold — noticeably cold. If it’s warm or room temperature, your compressor likely isn’t running. That could be a capacitor, refrigerant issue, or electrical problem — at that point you need a technician.
Warm air from your AC is always telling you something. It’s airflow, a mechanical failure, or a refrigerant issue. None of those are things you ignore and hope go away.
By Gregg DeMille, owner of Timber Creek Services in Farr West, Utah.
Need help with this? See AC Repair or call or text (801) 832-5302.