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.
Auxiliary heat strip diagnostics are included in the same visit when relevant.
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 Medford, WI.
A stuck reversing valve is the single most common reason a heat pump gets stuck in one mode. This is one of the most requested heat pump repair calls we get across Medford, WI.
We verify the defrost cycle actually triggers under test conditions. This is one of the most requested heat pump repair calls we get across Medford, WI.
We test heat strip elements and the relay controlling them separately. This is one of the most requested heat pump repair calls we get across Medford, WI.
Heat pump refrigerant charging follows different specs than standard AC systems, especially across heating and cooling modes. This is one of the most requested heat pump repair calls we get across Medford, WI.
We distinguish between the two before recommending any repair. Techs handling outdoor unit icing diagnostics carry the specific parts and tools this job calls for, not a generic kit.
Ductless mini-split heat pumps have their own fault-code language separate from central systems. 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.
Heat pump-trained technicians arrive with reversing valve and defrost diagnostic equipment already loaded.
Reversing valve, defrost cycle, and refrigerant charge are tested against heat pump-specific specs before any quote.
Most reversing valve and defrost board repairs finish same-visit with parts carried on the truck.

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.
They tested the relay separately from the strips themselves and found the actual fault fast.
Ductless heat pump in the addition threw a code I couldn't find anywhere online.

Often a stuck reversing valve, which controls whether the system is in heating or cooling mode.
If the unit stays iced for more than an hour, that's worth a service call.
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.
These systems have their own fault-code patterns that our techs are trained to read.
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Whether you're in the heart of Medford or one of the surrounding communities, dispatch routes the closest available technician.
☎ Call +1-866-805-8548 for Medford Service