Same-day AC repair
By Arman Hakobyan, lead technician2 min read
Most often the outdoor unit has stopped working: a failed capacitor or contactor, a tripped breaker, or a dirty condenser coil. Other causes are a clogged filter, a frozen coil, a thermostat set to Heat or Fan, or low refrigerant from a leak. Check the thermostat, the filter and the breaker first; the rest needs a technician.
Check these first (10 minutes, no tools)
- Thermostat: set to Cool, a few degrees below room temperature, fan on Auto. Replace its batteries if the display is faint.
- Filter: if it is gray and clogged, replace it. Restricted airflow can freeze the indoor coil and stop cooling.
- Breakers: look for a tripped AC or air handler breaker in the panel, and the disconnect switch next to the outdoor unit. Reset once only.
- Outdoor unit: is the fan spinning? If it hums but the fan does not turn, switch the system off at the thermostat and call. Running it this way overheats the compressor.
- Ice: if you see ice on the copper lines, set the system to Off or Fan only and let it thaw for a few hours.
The 7 usual causes
- Failed run capacitor: the most common summer failure in LA. The outdoor fan or compressor will not start. A same-visit fix.
- Bad contactor: the switch that powers the outdoor unit burns or sticks, especially after a hot season.
- Dirty condenser coil: dust, pollen and ash block heat rejection, so the system runs but cools poorly.
- Clogged filter or blocked returns: low airflow freezes the indoor coil, which then blocks airflow completely.
- Low refrigerant: a leak somewhere in the coil or lines. Adding refrigerant without finding the leak only buys weeks.
- Thermostat or wiring problem: a miswired or failing thermostat, or a damaged low-voltage wire outside.
- Failed compressor: the most expensive cause, usually on older systems. We price repair and replacement side by side.
What it costs to fix
A diagnostic visit is $89, credited to the repair. Capacitors, contactors and drain clearing start at $189. A leak search starts at $289. Compressor and coil replacements are quoted on site because they depend on the system and refrigerant.
Questions
Can I replace an AC capacitor myself?
It is possible but risky: capacitors store a dangerous charge even with power off, and the wrong value damages the motor. A technician also checks why it failed.
Why does my AC blow warm air only in the afternoon?
The system may be undersized or losing capacity from a dirty coil or low charge, so it cannot keep up at peak heat. Measuring the temperature split and pressures tells which.
Need it fixed today?
Open Mon-Sun 7 AM-9 PM. 24/7 emergency line.
Arman leads diagnostics at Airwork. He has spent nine years on residential systems across the San Fernando Valley and the foothills, from 1950s ranch houses with attic ducts to new heat pump installs, and writes our guides from what he sees on calls.
Airwork Heating & Cooling, Burbank, CA (CSLB #1148919). Published .More guides
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