AC Not Cooling in San Ramon

AC Not Cooling in San Ramon

San Ramon gets hot. Sitting inland in the Tri-Valley, July and August routinely push past 95, and cooling is the bigger HVAC workload here by a wide margin. That heat is exactly when air conditioners fail, because the compressor and capacitor are working hardest on the hottest afternoon. A unit that runs but blows warm on a 98-degree day is a problem worth fixing now, before the next heat spike.

It is usually one part, not a dead system. The tract homes in Windemere and Twin Creeks and the newer Gale Ranch and Dougherty Valley developments throw the same failures: a worn capacitor, a leak, a dirty condenser coil, or a frozen indoor coil from low airflow. We read the system's real numbers with gauges and a meter rather than guessing.

On the older tract homes the AC condensers and furnaces are getting up in years, so we are honest when a repair is propping up a system near the end of its life. We give you the repair cost and, where it is close, the replacement numbers side by side. Our shop is here in town, so we respond fastest in San Ramon and can usually get a cooling call handled in one visit.

Common causes

Run capacitor failure in peak heat. The most common San Ramon warm-air call, and it spikes on the hottest days. The compressor or fan hums but will not start. We meter the capacitor against spec and replace it on the spot. Cheap part, fast fix, and it fails faster in our inland heat.

Refrigerant leak. A low charge leaves the house warm and the system running constantly. We confirm with pressure readings and trace the leak instead of just topping off. On older tract-home systems still on R-22 we put the replacement math on the estimate, since the leak will return.

Dirty condenser coil. Tri-Valley dust and landscaping cake the outdoor coil so it cannot shed heat in 95-plus weather, and the unit runs without cooling. We wash the coil and confirm the temperature split recovers. Often the whole fix on an otherwise healthy system.

Aging compressor not starting. On the older systems common in the original tracts, the compressor may struggle or fail to start while the fan still spins. We test the start draw and the contactor. A failed compressor on a system this old usually moves the conversation toward replacement, and we lay out both numbers clearly.

Frozen evaporator coil. Low airflow from a clogged filter or weak blower ices the indoor coil and cooling stops. We thaw it and fix the airflow cause rather than just clearing the ice. Common late in a long hot stretch when filters are overdue.

Pitted contactor. The relay that energizes the compressor pits and wears, so the compressor never reliably engages. We inspect for pitting and chatter and replace it if worn. A low-cost part that takes a healthy system offline.

How we diagnose it

• Read refrigerant pressures and the temperature split to tell a charge problem from an airflow or electrical one.
• Meter the run capacitor and inspect the contactor, the failures that climb during San Ramon heat waves.
• Wash and inspect the condenser coil and confirm the outdoor unit can reject heat in inland heat.
• On older tract-home systems, test compressor start draw and assess whether repair or replacement makes more sense.
• Check the indoor coil for ice and the filter and blower for the low airflow that causes freeze-ups.

$75 diagnostic, credited toward any repair over $200. You get a written quote before any work begins.

AC Not Cooling in San Ramon: common questions

Nearby and related

AC Not Cooling near San Ramon: Danville · Alamo · Dublin · Pleasanton .

This is usually a ac repair in San Ramon job. See our ac repair overview or the San Ramon service area.