Heat Pump Not Heating in Los Gatos, CA

Heat Pump Not Heating in Los Gatos

A heat pump that won't heat sounds like a catastrophe and usually isn't. The unit is a reversing refrigeration circuit. When it stops producing heat, the cause is most often a reversing valve hung in cooling, a defrost board that left the coil iced over, a low charge from a slow leak, or a contactor that never closed. The expensive parts, compressor and coils, are typically intact.

Los Gatos makes this more interesting because of where homes sit. Hillside properties catch cool, damp marine air, and the shaded lots tend to hold morning fog longer. Damp cold mornings are exactly when an outdoor coil frosts up, so a defrost fault tends to show itself here before it would in a drier inland town. Winters are mild and well inside heat pump range, so the climate is not the problem. A failed defrost cycle that lets ice build on the coil is.

The housing varies as much as the terrain. Older homes near downtown were often retrofitted with ductless mini-splits, while many hillside houses run multi-zone ducted systems. The diagnostic path differs by system, so the first thing we do is identify what you actually have, then trace the fault to the part and put the number on a written estimate.

Common causes

Outdoor coil iced over from a defrost fault. Damp, foggy Los Gatos mornings frost the outdoor coil, and a working heat pump clears it on a timed defrost cycle. A bad defrost sensor or control board skips that cycle, the coil glazes with ice, and the unit can no longer pull heat from the air. We watch a defrost cycle, check sensor resistance, and confirm the board terminates correctly before replacing anything.

Reversing valve stuck in cooling. If the reversing valve hangs mid-stroke or its solenoid coil fails, the heat pump keeps running in cooling mode and blows cold air all winter. We read temperatures across the valve and test the solenoid coil. A failed coil is an inexpensive swap; a stuck valve body is a brazed repair we quote up front.

Low refrigerant charge. A slow leak quietly drops heating capacity over a couple of seasons. The unit runs long, makes weak heat, and may ice up. We gauge the system, check it against spec, locate the leak, repair it, and then recharge. We do not top off and walk away; that just delays the same call.

Mini-split outdoor unit or board on a retrofit. Many older Los Gatos homes near downtown were retrofitted with ductless mini-splits. When one of these stops heating, it is often a communication fault between the head and the condenser, a failed outdoor control board, or a sensor. These read error codes, so we pull the code, interpret it against the manufacturer's chart, and diagnose from there.

Failed contactor or capacitor. A pitted contactor or weak run capacitor leaves the outdoor unit silent or humming. The compressor never starts, so no heat moves. Both are quick meter checks and both ride on our truck, so these are usually same-visit fixes.

Backup heat not engaging. Ducted hillside systems usually carry electric strip heat for cold starts and for the minutes the heat pump spends in defrost. A failed sequencer or strip leaves you cold on the worst mornings. We check strip continuity and the control wiring that calls for it.

How we diagnose it

Identify the system first, ducted multi-zone or ductless mini-split, since the diagnostic path differs.
Inspect the outdoor coil for ice and watch a full defrost cycle, then check the defrost sensor and board.
Read line temperatures across the reversing valve to confirm the unit is genuinely in heating mode.
Gauge the refrigerant charge against spec and leak-check if readings are low.
On mini-splits, pull and interpret error codes; on ducted systems, meter the contactor, capacitor, and aux heat.

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

Heat Pump Not Heating in Los Gatos: common questions

Can you reach a Los Gatos hillside address, or is that out of range?

We cover Los Gatos hillside and downtown both. We are based in San Ramon and service the full Bay Area. Tight hillside driveways and condenser placement are normal for us; tell us the access situation when you call (925) 999-4095 and we will plan around it.

Why does my Los Gatos heat pump ice up on foggy mornings?

Some frost on the outdoor coil during cold, damp mornings is normal, and a healthy unit melts it off automatically during a short defrost cycle. The fog and shade on the lower hillside lots just make frost more likely. If the coil stays caked in ice, the defrost cycle is failing, which is a sensor or control board repair, not a sign the unit is finished.

My mini-split is showing an error code and not heating. What does that mean?

The code is the unit telling you what it detected: a sensor fault, a communication loss between the head and outdoor unit, or a pressure problem. We read the code, check it against the manufacturer's table, and confirm with our own measurements. It points the diagnosis; it rarely means the system is dead.

Nearby and related

Heat Pump Not Heating 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.