Heat pumps fail differently than standard AC or furnace systems, and diagnosing them requires understanding the reversing valve and defrost board specifically.
A heat pump stuck in one mode, or one that's iced over and won't defrost, gets diagnosed with the right tools for that specific failure mode.
If you're dealing with a system stuck blowing cold air in heating mode, an outdoor unit that's iced over and won't run its defrost cycle, or a system that switches modes but never actually reaches set temperature, you already know a heat pump that seems to be 'not heating' is often actually a reversing valve or defrost cycle problem, which a technician trained mainly on standard AC systems can easily misdiagnose.

Waiting rarely saves money and often turns a same-day repair into a longer, more involved job.
AAA Pro HVAC built its heat pump repair process around one idea: diagnose first, quote honestly, fix it right.
We're licensed, insured, and staffed with techs who've spent years specifically on heat pump repair, not general handyman work with an HVAC certificate bolted on.

Our techs are specifically trained on reversing valves, defrost boards, and auxiliary heat systems, not just general AC repair logic.
Heat pumps run in both summer and winter, so we treat heat pump failures as urgent regardless of season.
You get a quoted price after the reversing valve and defrost cycle are actually tested, not billed for trial-and-error.
We test reversing valve solenoids, defrost thermostats, and control board timing directly.
Every job starts with a real diagnosis, not a guess — here's the full scope of what our heat pump repair technicians handle across Lagunitas, CA.
We test the valve's solenoid directly rather than assuming based on symptoms alone. Techs handling reversing valve diagnosis & repair carry the specific parts and tools this job calls for, not a generic kit.
An outdoor unit that ices over and never defrosts usually points to a failed defrost thermostat or control board timing issue. Techs handling defrost cycle & control board repair carry the specific parts and tools this job calls for, not a generic kit.
Backup electric heat strips that fail can leave a home without adequate heat during the coldest stretches. This is one of the most requested heat pump repair calls we get across Lagunitas, CA.
Heat pump refrigerant charging follows different specs than standard AC systems, especially across heating and cooling modes. Techs handling refrigerant charge & leak detection carry the specific parts and tools this job calls for, not a generic kit.
We distinguish between the two before recommending any repair. This is one of the most requested heat pump repair calls we get across Lagunitas, CA.
Indoor head unit and outdoor condenser are diagnosed as a connected system. Techs handling ductless heat pump system repair carry the specific parts and tools this job calls for, not a generic kit.

That detail determines which specialized tools ride along.
We confirm your Lagunitas address and a realistic arrival window.
Flat-rate pricing follows the confirmed diagnosis.
Workmanship is guaranteed and documented on your invoice.

System would only blow cold air no matter what mode I selected.
Turned out the defrost thermostat had failed, so it never actually triggered the defrost cycle.
Auxiliary heat strips weren't kicking in during a cold snap and the house couldn't keep up.
Tech recognized it immediately as a defrost-related fault specific to that brand.

Often a stuck reversing valve, which controls whether the system is in heating or cooling mode.
Some frost during a normal defrost cycle is expected; ice that never clears points to a defrost board or thermostat fault.
Heat pumps have a reversing valve, defrost cycle, and often auxiliary heat strips that standard AC systems don't have.
If auxiliary heat isn't kicking in properly, that's a specific fault we can test for.
Yes — indoor head units and outdoor condensers on ductless heat pump systems are within our service scope.
Call for a live arrival estimate based on current demand.

Our heat pump repair crews are positioned throughout Lagunitas, CA to keep response times realistic, not just promised.
☎ Call +1-866-805-8548 for Lagunitas Service