Most "AC not cooling" calls in Elk Grove and Sacramento trace back to a handful of causes. Some you can fix in five minutes. Others need a licensed technician. Work through these in order, and stop at anything that involves opening panels or electrical parts.
1. Check the thermostat
- Mode is set to Cool, not Heat or Off
- Setpoint is a few degrees below the room temperature
- Fan is on Auto, so you are not just moving warm air
- Replace the batteries if the screen is blank or dim
2. Check the breakers
The outdoor condenser and the indoor furnace or air handler usually have separate breakers. Reset a tripped breaker once. If it trips again, leave it off and call: repeated trips point to an electrical or compressor problem.
3. Replace a dirty air filter
A clogged filter starves the system of airflow, which cuts cooling and can freeze the indoor coil. In summer and during wildfire smoke season, check the filter monthly.
4. Look for ice
Frost on the copper refrigerant lines or the indoor coil means the system cannot move heat. Turn cooling off and run the fan only for a few hours to thaw it. If ice comes back, the cause is usually low airflow or low refrigerant, and refrigerant work needs a licensed technician.
5. Check the outdoor unit
- Is the fan on top spinning when the system calls for cooling?
- Clear leaves, cottonwood fluff and dryer lint, and keep about two feet of space around it
- Gently rinse the coil fins with a garden hose (never a pressure washer)
If the unit hums but the fan does not spin, the capacitor has often failed. Do not poke the fan or open the panel: capacitors hold a charge even with the power off. That is a quick AC repair.
6. Check the condensate drain
Many systems have a float switch that shuts cooling off when the drain line backs up. Water in the drain pan or near the indoor unit is the giveaway. A clogged drain is common in Sacramento-area attics and is part of every spring tune-up.
7. Set realistic expectations on extreme days
Most home systems are sized to hold about 75°F indoors at Sacramento's design temperature of roughly 100°F. On a 108°F afternoon a healthy system can run nonstop and still drift a few degrees above the setpoint. If the air from the vents is cool and the house recovers in the evening, the system is likely doing its job.
When to call a professional
Call right away if you smell burning, a breaker keeps tripping, ice returns after thawing, the outdoor unit hums without the fan turning, or water is leaking into ceilings or walls. AIRWRX is a CSLB-licensed C-20 contractor in Elk Grove: call (916) 715-0076 and we will tell you what we find and what it costs before any work starts.
Deciding between fixing an older system and replacing it? Read AC repair or replace.