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Heco HVAC · Experience since 2006 · California contractor license #1050351
Detailed homeowner guides explain safe checks, possible causes and when to request professional diagnosis.
Search what you observe—not what you think the failed part is. Several HVAC faults can produce the same symptom, and an on-site diagnosis is often needed before choosing a repair.
8 matching answers
Clear filtersIt determines when the outdoor coil needs defrost and controls the temporary defrost sequence using sensor/input logic appropriate to the model.
Possible causes include a defrost sensor, control board, reversing-valve/control issue or other fault. Persistent outdoor icing should be diagnosed before it blocks airflow or damages the unit.
Yes. A restriction can reduce refrigerant flow and capacity, but diagnosis requires temperature/pressure measurements and should not be inferred from symptoms alone.
A technician verifies thermostat/control signals, solenoid operation and refrigeration-system behavior before condemning the valve itself. Reversing-valve replacement is sealed-system work.
The problem can involve thermostat/reversing-valve control, defrost logic, refrigerant performance, auxiliary heat or other components. Because heating and cooling share much of the same equipment, mode-specific diagnosis is important.
On many heat pumps the outdoor fan is intentionally stopped during defrost so heat can be directed to the outdoor coil. This can be normal when it occurs only as part of a proper defrost cycle.
A crankcase heater helps reduce refrigerant migration into compressor oil during off periods on systems designed to use one. Its operation is equipment-specific.
On equipment that requires one, prolonged refrigerant migration and liquid-rich startup can contribute to compressor stress. The heater and controls should be checked according to manufacturer guidance.
Equipment condition still requires professional evaluation. For regulations, rebates and efficiency guidance, Heco checks authoritative sources and identifies items that can change.
Tell Heco the symptom, equipment type, property type and location. We will help identify the next practical step.