1. The thermostat is set wrong
Check that the thermostat is set to Cool, that the setpoint is below the room temperature, and that the fan is on Auto. With the fan on On, it keeps blowing between cooling cycles, and that air will feel warm. If the screen is blank, replace the batteries.
2. The air filter is clogged
A dirty filter chokes airflow. The system may run but move very little air, and over time the indoor coil can freeze. Check the filter and replace it if it looks gray or packed with dust.
3. The outdoor unit is not running
If the indoor fan blows but the outdoor unit is silent, check the breaker for the air conditioner and the disconnect switch near the outdoor unit. If a breaker has tripped, reset it once. If it trips again, leave it off and call.
4. The outdoor coil is dirty or blocked
The outdoor unit has to shed heat. Leaves, dryer lint, overgrown plants or stored items around it make that hard. Clear at least a couple of feet around the unit. You can gently rinse the outside of the coil with a garden hose (not a pressure washer) with the power off.
5. The indoor coil is frozen
Low airflow or low refrigerant can make the indoor coil ice over. Signs include ice on the refrigerant lines or water around the indoor unit. Turn cooling off and run the fan only to let it thaw, then fix the cause. A frozen coil usually comes back until the underlying problem is fixed.
6. Low refrigerant from a leak
An air conditioner does not use up refrigerant. If it is low, there is a leak, and simply adding refrigerant only delays the next breakdown. Finding and repairing the leak is a job for a technician.
7. A failed capacitor or contactor
These electrical parts help the outdoor fan and compressor start. When one fails, you may hear a hum from the outdoor unit while the fan does not spin, or the unit may not start at all. This is a common repair, but it needs a technician because of the stored charge.
When should you call a technician?
- A breaker trips again after one reset
- You see ice that returns after thawing
- You hear humming, grinding or buzzing from the outdoor unit
- The system runs constantly and the house still gets warmer
- There is water pooling near the indoor equipment
- You smell burning or see scorching
Jordan diagnoses the problem first and tells you plainly whether it is a repair or time to compare AC replacement. Regular AC tune-ups catch many of these issues before the first hot day.
Talk it through with Jordan
Jordan personally handles every call and every quote. Tell him what is going on, and he will tell you plainly what it needs.
Call (650) 650-2653 — that’s 650-650-COLD. Monday–Friday, 7am–5pm.