Heat Pump Not Cooling in Lafayette, CA

Heat Pump Not Cooling in Lafayette

Lafayette summers run a little cooler than Danville, typically 85 to 90, but the hillside homes still load up their air conditioning hard on west-facing afternoons. When a heat pump keeps running and the house won't cool, the cooling cycle has a fault somewhere. A heat pump cools by reversing its refrigerant flow, so we diagnose a no-cool heat pump the same way we'd diagnose any air conditioner.

Most of the time this is one failed component, not a dead system. The unit that heated your home fine all winter still has a working compressor. Something on the cooling side has changed. A stuck valve, a low charge, a clogged coil, or a bad capacitor will each produce the same warm-air symptom, and that narrows where we look.

What's particular to Lafayette is access. A lot of these custom hillside homes sit on grade-separated lots, and the condenser is often tucked against landscape or down a slope with a tight line-set run through framing. We scope that at the visit so the repair plan and the estimate account for how we actually reach the equipment, on top of what's wrong with it.

Common causes

Reversing valve stuck in heat mode. If the valve that flips the system between heating and cooling sticks, the heat pump runs but blows warm air when you ask for cool. We test the valve solenoid and read line temperatures to confirm it isn't shifting, then replace the solenoid or the valve. On older Lafayette units this is a routine cause, not a rare one, and we confirm it by test.

Low refrigerant from a leak. A heat pump low on charge runs constantly and never gets the house cold. We locate the leak first with electronic detection or a nitrogen pressure test, repair it, then evacuate and recharge to the manufacturer's spec. On hillside homes where the line set runs a long way through framing, the joints and flares are the spots we check hardest.

Dirty outdoor coil. Lafayette's mature tree cover drops a lot of leaf litter and pollen onto condensers, and a coil packed with debris can't shed heat. Capacity drops and head pressure rises. We clean the coil and clear its clearance, then recheck pressures. On the tucked-away hillside condensers, restricted airflow around the unit makes this worse.

Failed capacitor or contactor. The capacitor starts the compressor and fan; the contactor switches power to them. When one fails, you may hear a hum or get the fan running with no cold air. We meter both and carry common values on the truck, so this is often fixed on the first visit even on a hard-to-reach unit.

Frozen indoor coil from low airflow. A clogged filter or weak blower starves the indoor coil and it ices up, which kills cooling output. Lafayette's tight crawl spaces and low attic clearances make some of these air handlers hard to service, which is exactly why airflow problems get neglected. We thaw the coil, fix the airflow restriction, and confirm it stays clear.

Thermostat set or wired wrong. Sometimes the simplest answer: the thermostat is in heat or the wrong mode, or a smart-stat lost its configuration after a power blip. We confirm the thermostat is actually calling for cooling and energizing the reversing valve before we open the refrigerant circuit.

How we diagnose it

Scope equipment access on the lot so the repair plan matches how we reach a hillside or grade-separated condenser.
Confirm the thermostat is calling for cooling and check the reversing valve is shifting on that call.
Read suction and head pressures against outdoor temperature to judge charge and heat rejection.
Test the capacitor and contactor, and clean and inspect the outdoor coil for tree debris.
Check the indoor coil and filter for ice and airflow restriction in the crawl space or attic handler.

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

Heat Pump Not Cooling in Lafayette: common questions

Lafayette has tricky hillside lots. Does that change your response time or pricing?

Response time, no. We cover Lafayette out of San Ramon daily and a no-cool call gets priority routing. Call (925) 999-4095. Access can affect pricing on bigger repairs if a condenser needs a crane or special placement, which is why we scope it on site and put the real number on a written estimate before any work.

Our summers are milder than Danville's. Is it worth fixing a heat pump that won't cool, or should I just wait it out?

Lafayette tops out around 85 to 90, but hillside homes with western exposure still run hot in the afternoon, and a system left running low on charge or frozen can damage its compressor. The fix is usually one part and not expensive. Letting it limp can turn a small repair into a compressor replacement.

It heated fine all winter but won't cool now. Is the whole unit shot?

Almost never. If it heated fine, the compressor and the basic system are healthy, and the problem is on the cooling side: most often a stuck reversing valve or low refrigerant from a leak. Both are one-visit diagnostics. The diagnostic is $75 and gets credited toward the repair when it's over $200.

Nearby and related

Heat Pump Not Cooling near Lafayette: Orinda · Moraga · Walnut Creek · Alamo .

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