AC Not Cooling in Palo Alto

AC Not Cooling in Palo Alto

An AC that runs but will not cool is almost always one failed part rather than a dead system. A capacitor, a contactor, the refrigerant charge, or airflow across the coil. We diagnose with gauges and a meter and show you the reading before we quote.

Palo Alto's housing shapes the call more than the weather does. The Eichler tracts in Greer, Greenmeadow, and Fairmeadow cannot take traditional ducted AC because of the post-and-beam ceilings, so cooling in those homes is almost always a multi-head ductless mini-split. When one of those quits cooling, the usual suspects are a dirty indoor filter, a head that is not draining, or a low charge, not a failed central compressor. The heritage Spanish and Mediterranean stock in Old Palo Alto and Crescent Park often runs newer high-efficiency equipment fitted carefully into older architecture, and those systems fail in more conventional ways.

The climate is genuinely mild, summer highs usually in the low to mid 80s with heavy fog, so equipment here is not stressed the way an inland system is. That usually means a no-cooling call is a single serviceable part. We work carefully around the architecture, keep the job clean, and put the actual diagnosis on a written estimate.

Common causes

Dirty filter or clogged drain on a ductless head. The most common no-cooling cause in Palo Alto's Eichlers and additions. A choked filter or a head that will not drain ices up and blows warm. We clean the filter and coil, clear the condensate path, and confirm the head cools before chasing anything bigger.

Low refrigerant on a mini-split. A ductless system low on charge blows lukewarm. We read pressures and look for the leak at the flare connections, which are the usual point on mini-splits. We find and fix the leak rather than recharging a system that will only lose it again.

Failed capacitor on a central system. On the heritage homes running central equipment, a weak capacitor stops the compressor from starting and warm air comes out. We meter it against its rating and replace a weak one from truck stock.

Frozen evaporator coil. Low airflow from a dirty filter or weak blower freezes the indoor coil. We thaw it, then measure airflow to find the restriction instead of treating the ice as the cause.

Dirty condenser coil. An outdoor coil packed with dust cannot reject heat, so cooling fades on the warmer fog-free afternoons. We check head pressure, wash the coil, and clear the airflow around the unit.

How we diagnose it

• Whether the home cools with a ductless system or central equipment, since most Eichlers are ductless and the failure modes differ.
• On mini-splits: indoor filter, coil cleanliness, and the condensate drain at each head.
• Suction and head pressure with gauges to read charge and find leaks at flare connections.
• Capacitor and contactor condition on central systems in the heritage stock.
• Condenser coil cleanliness and clearance at the outdoor unit.

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

AC Not Cooling in Palo Alto: common questions

Nearby and related

AC Not Cooling near Palo Alto: Menlo Park · Los Altos · Mountain View .

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