What It Means
Outdoor inverter drive board zero-crossing detection circuit fault.
York All Systems
York Error Code E6
Troubleshooting guide for the York system fault E6.
Possible Causes
- Inverter drive board zero-cross detection circuit connection loose.
- AC power quality issues such as voltage sags or phase noise.
- Failing component on zero-cross sensing circuit.
- Faulty outdoor inverter PCB requiring replacement.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis
E6 indicates a fault in the outdoor unit's zero-crossing detection circuit, which the inverter drive board uses to synchronize compressor switching with the AC waveform. This is an electrical timing/detection fault on the drive board itself, distinct from E8 (a fan motor speed-feedback fault) and EA (an actual compressor overcurrent event) — E6 can trip even when the compressor and fan are otherwise mechanically sound if the zero-cross signal is missing or corrupted. Because it affects the outdoor drive board's core switching logic, it typically shuts down compressor operation for the outdoor unit.
All Recorded Causes
Inspect the outdoor inverter/drive board's zero-cross detection circuit connections and check for loose or corroded terminals. Verify incoming AC power quality — voltage sags, noise, or an unstable phase can disrupt zero-cross detection. Check for a failing or damaged drive board component in the zero-cross sensing circuit. Replace the outdoor PCB/drive board if the fault persists after ruling out wiring and power quality.
Verify Before Replacing Parts
- Confirm the exact York model family and default context before acting on a generic code description.
- Confirm board LEDs, wiring polarity, and model compatibility before replacing control boards — this York fault points at inspect the outdoor inverter/drive board's zero-cross detection circuit connections and ch….
- Check for intermittent communication faults caused by connectors, moisture, or damaged harnesses, and rule out verify incoming AC power quality — voltage sags, noise, or an unstable phase can disrupt z….
- After the correction, run the system long enough to confirm the default fault does not return under normal load.
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