Heat Pump Not Cooling in Los Gatos, CA

Heat Pump Not Cooling in Los Gatos

Los Gatos hillsides have the trickiest cooling loads we deal with. Design temps swing from the high 80s into the mid-90s depending on elevation and orientation, and a west-facing upper room can call for cooling all afternoon while a shaded lower floor stays cool. So when a heat pump runs but won't cool, it shows up fastest in exactly those hot rooms. A heat pump cools by reversing its refrigerant flow, which is why we diagnose a no-cool heat pump the same way we'd diagnose any AC.

What's specific to these homes is the equipment mix. Many run a central system per floor plus a supplemental ductless head on the worst west-facing room, so the question on arrival is which piece of equipment actually serves the room that's hot. That answer changes the whole diagnosis, because a ductless head and a central condenser fail in different places and get tested differently.

It's rarely a dead system. If the heating worked all winter, the compressor on that loop is fine and something cooling-specific has changed. A stuck reversing valve, a failed capacitor, a dirty coil, or low refrigerant from a leak are each a single-part fault with a defined fix and a written number before any work begins. We start by confirming the right equipment, then test that piece directly.

Common causes

Reversing valve stuck in heat mode. The reversing valve switches the heat pump between heating and cooling. When it sticks, the unit runs but blows warm air on a cooling call. We test the solenoid and read line temperatures to confirm, then replace the solenoid or valve. On a multi-zone hillside home we check the valve on the specific system feeding the hot west-facing zone.

Low refrigerant from a leak. A heat pump low on charge runs constantly and never gets the room cold, which on a 4 PM west-facing upper floor means it can't keep up. We find the leak first with electronic detection or a nitrogen pressure test, repair it, then evacuate and recharge to spec rather than topping off and leaving the leak in place.

Failed capacitor or contactor. The capacitor starts the compressor and fan; the contactor switches power to them. When either fails, you may get the fan moving air with no cooling, or a unit that hums and trips. We meter both and carry common sizes on the truck, so this is frequently a same-visit fix on the affected zone.

Dirty or shaded outdoor coil. Los Gatos hillside lots are wooded, and condenser coils pack with leaf debris that keeps them from shedding heat. Capacity drops, pressures rise. We clean the coil and clear clearance, then recheck pressures. With multiple condensers per home, we confirm we're servicing the one tied to the warm room.

Ductless head not cooling. Many homes here use a supplemental ductless head on the worst west-facing room. When that head won't cool, the causes are the same family, low charge, a control fault, or a dirty coil, but it's a separate piece of equipment from the central system. We test the head and its outdoor unit directly rather than chasing the central system.

Frozen indoor coil from low airflow. A dirty filter or weak blower starves the indoor coil and it freezes, shutting cooling down to that zone. On multi-zone homes a stuck damper can do the same to one coil. We thaw it, find the airflow cause, and confirm it stays clear before we leave.

How we diagnose it

Identify which zone or piece of equipment actually serves the warm room, central system or supplemental ductless head.
Confirm that zone's thermostat is calling for cooling and verify the reversing valve shifts on the cooling call.
Read suction and head pressures against outdoor temperature and scan for a refrigerant leak.
Test the capacitor and contactor, and clean and inspect the wooded-lot outdoor coil tied to the affected zone.
Check the indoor coil, filter, and zone dampers for ice and airflow restriction in that part of the house.

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

Heat Pump Not Cooling in Los Gatos: common questions

Do you service Los Gatos, and how quickly can you reach the hillside neighborhoods?

Yes, we cover Los Gatos and the wider South Bay, including 95030 and 95032. Call (925) 999-4095 for an honest arrival window. No-cool calls get priority routing in warm weather, with same-day being best-effort rather than guaranteed.

Only my west-facing upstairs room won't cool in the afternoon. Is the heat pump failing?

Maybe, or maybe that room is served by a single zone or a ductless head that has a specific fault while the rest of the house is fine. Los Gatos hillside homes have big load differences between floors and orientations. We confirm which equipment serves that room and diagnose that piece, instead of assuming the whole system failed.

It heated fine all winter but won't cool now. What does that point to?

That the compressor and heating side are healthy and the fault is cooling-specific, usually a stuck reversing valve or low refrigerant from a leak on the affected zone. Both are one-visit diagnostics. Our diagnostic is $75, credited toward the repair when it runs over $200.

Nearby and related

Heat Pump Not Cooling near Los Gatos: Saratoga · San Jose · Cupertino .

This is usually a heat pump installation & service in Los Gatos job. See our heat pump installation & service overview or the Los Gatos service area.