The short answer
Palo Alto AC repair starts with the clue you notice: an unusual sound, a smell, water, or rooms that stay warm. We confirm the cause with electrical and refrigerant testing, explain the options and repair common failures on the first visit whenever the part is in stock.
Cooling problems in Palo Alto tend to announce themselves in one of three ways: a sound, a smell or a room that will not cool down. Each of those clues narrows the list of likely causes before anyone opens a panel. ExpertFlow HVAC Repair Service, located about four miles away in Los Altos, repairs central air conditioners, heat pumps and ductless systems for households in 94301, 94303, 94304 and 94306. This page is organized around the clues you will actually notice, followed by how our technicians confirm the problem and what happens next.
Clue: a new or unusual sound
Equipment that has been running quietly and suddenly gets louder is telling you something. A buzzing or humming outdoor unit with a fan that will not turn usually means the capacitor that starts the motor has failed. A rhythmic clicking at startup may be a contactor or relay struggling. Grinding or squealing from the indoor blower points to worn bearings, and a rattle can be as simple as a loose panel or a twig inside the condenser fan guard.
Shut the system off if you hear grinding or a loud bang, and avoid restarting it repeatedly. A motor or compressor under strain can turn a moderate repair into a large one.
Clue: an odd smell from the vents
A musty smell when cooling starts often traces to moisture sitting in a drain pan or on a dirty coil. A burning or hot electrical odor deserves immediate attention: turn the system off at the thermostat and the breaker and call for service. A faint sweet or chemical smell can sometimes accompany a refrigerant leak.
Smells near an attic or closet air handler can also come from dust that settled over the long, mild months burning off on the first run, which fades quickly. If it lingers, have it checked.
Clue: water, ice or rooms that stay warm
Water around the indoor unit, a ceiling stain under an attic air handler, or a float switch that has shut the system down all point to the condensate drain. Ice on the copper line at the outdoor unit or on the indoor coil suggests restricted airflow or low refrigerant. Rooms that stay warm while others feel fine can be a duct problem rather than an equipment failure, especially in older Palo Alto homes where attic ducts may have slipped apart over time.
- Water near the air handler: clogged drain line, cracked pan or failed condensate pump
- Frost on lines or coil: dirty filter, weak blower or refrigerant leak
- One room warm, others cool: disconnected duct, closed damper or blocked register
- Whole house warm, air moving: outdoor unit not running or compressor fault
- No air at all: blower motor, control board, thermostat or tripped safety switch
How our technicians confirm the cause
Clues guide the visit, but measurements decide it. We test capacitors and contactors, check voltage and amp draw on motors and the compressor, read refrigerant pressures alongside line temperatures to calculate superheat and subcooling, and measure the temperature drop across the indoor coil. For suspected leaks we inspect brazed joints, service valves and coil surfaces and use electronic detection before recommending a repair.
On ductless systems we read stored fault codes, check communication wiring between indoor and outdoor units, clean filters and coils if needed and confirm drain flow from each head.
After the diagnosis
You will hear what failed and why, in plain language, along with the repair options. Capacitors, contactors, fan motors, drain clearing and thermostat fixes are usually completed during the same visit. Larger items, such as a compressor, an indoor coil or a leak repair, are quoted in writing first.
If the equipment is older and failing frequently, we will say so and explain what a replacement would involve, including heat pump options that would also handle winter heat. The decision remains yours, and Bay Area Air District rules do not require replacing a working gas furnace in the process. We also repair cooling systems in Los Altos Hills, Mountain View, East Palo Alto, Atherton and Portola Valley.
More services in Palo Alto
- Heating Repair in Palo Alto
- Heat Pump Installation in Palo Alto
- AC Installation in Palo Alto
- Furnace Repair in Palo Alto
