Home AC Repair in Antioch & East Contra Costa
Diagnosis and repair for AC that won't cool
When your home air conditioner quits on a 100-degree afternoon, you want a straight answer about what failed and what the fix involves. We repair central air conditioners and split systems in houses, apartments and small commercial buildings across Contra Costa. Common problems include failed capacitors and contactors, frozen evaporator coils, refrigerant leaks, clogged condensate drains, worn fan motors and compressors that won't start. We also keep older R-22 systems running when that still makes sense.
Why choose Blue Star
Our technician tests the system before recommending anything: electrical readings, refrigerant pressures, airflow and the temperature drop across the coil. Then we show you what we found and give you a price for the repair. If the unit is near the end of its life, we tell you so and price a replacement too, so you can compare the two side by side.
- Capacitors and contactors
- Refrigerant leak search
- Frozen coils and low airflow
- Condensate drain clogs
- Fan and blower motors
- Thermostat and wiring faults
Where we work
AC repair calls peak in East County, where July highs average around 91F and the Antioch station has recorded 117F. Afternoon Delta breezes push dust and farm debris into condensers in Oakley, Brentwood, Discovery Bay and Byron, so dirty coils and overheated motors are common. Pittsburg and Bay Point have many rentals with aging split systems. In Concord, Walnut Creek and Pleasant Hill, older homes often have undersized returns that starve the coil and freeze it on hot days.
Major corridors
- SR-4
- SR-160
- Lone Tree Way
- Deer Valley Rd
- Railroad Ave
- Brentwood Blvd
- Ygnacio Valley Rd
- I-680
Find your town
4.9 stars on Google
Read more reviewsColton was great. He found the problem right away and did a temporary fix to get my a/c running until he could get the right part ordered. He also made sure every inside was working well.
Questions we hear
Why is my AC running but not cooling?
The most common causes are a dirty filter or condenser coil, a failed capacitor that keeps the outdoor fan or compressor from starting, low refrigerant from a leak, or an iced-over indoor coil. Check the filter and make sure the outdoor unit is running and clear of debris. If it still blows warm, turn the system off so the compressor isn't damaged, and call us.
Why is there ice on my AC lines or coil?
Ice usually means too little airflow or too little refrigerant. A clogged filter, closed vents, a weak blower or a dirty evaporator coil can drop the coil below freezing, and a refrigerant leak does the same. Switch the system off or to fan only so it thaws, replace the filter, and have it checked if it ices again. Running it frozen can ruin the compressor.
Can you still repair an old R-22 air conditioner?
In many cases, yes. New R-22 has not been produced in the U.S. since 2020, so repairs rely on recovered and reclaimed refrigerant, which makes recharging costly. A small, findable leak on a system in good shape can be worth fixing. A large leak or a failed compressor on an R-22 unit usually points toward replacement. We give you both options before any work.
Is it worth repairing an AC that is 15 years old?
Sometimes. A capacitor, contactor or fan motor is a modest repair that can keep an older unit running for years. A big repair, like a compressor or coil, on a 15-year-old system is often money better put toward a new one, especially since new systems use newer refrigerants and run more efficiently. We look at age, condition and repair history and tell you which way we would go.
What should I check before calling for AC repair?
Make sure the thermostat is set to cool and below room temperature, and check its batteries. Look at the breakers for the indoor and outdoor units, and confirm the disconnect switch next to the outdoor unit is on. Replace a dirty filter. If a breaker trips again after one reset, leave it off and call us, since repeated tripping usually points to an electrical or compressor problem.
Related services
All servicesBlue Star Heating & Air is just a call away!
AC not cooling? Call (925) 584-2428 Monday through Friday, or send a repair request and tell us what the system is doing.