What It Means
Outdoor unit incoming AC supply voltage out-of-range trip.
York All Systems
York Error Code F19
Troubleshooting guide for the York system fault F19.
Possible Causes
- Incoming supply voltage measured above or below safe limits.
- Loose or corroded electrical connections causing voltage sag.
- Circuit overloaded by other electrical equipment.
- Faulty outdoor PCB voltage-sensing circuit.
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
F19 indicates the outdoor unit's incoming supply voltage has moved outside its acceptable operating range, either too high or too low, as measured at the outdoor PCB. Unlike F22, which monitors current draw, F19 is strictly a voltage-quality fault and does not necessarily mean the unit is drawing excess current. Because unstable supply voltage risks damaging the compressor and inverter components, the outdoor unit typically shuts down compressor operation as a protective measure, affecting all indoor units served by that outdoor unit until voltage is confirmed stable and within range.
All Recorded Causes
Measure incoming line voltage at the outdoor disconnect and compare against the unit's rated voltage range. Check for a loose or corroded connection anywhere in the supply run that could cause voltage drop under load. Look for other loads on the same circuit causing sag, or an undersized supply conductor/breaker. Inspect the outdoor PCB's voltage-sensing circuit if line voltage measures normal but the fault persists.
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 measure incoming line voltage at the outdoor disconnect and compare against the unit's rat….
- Check for intermittent communication faults caused by connectors, moisture, or damaged harnesses, and rule out check for a loose or corroded connection anywhere in the supply run that could cause volta….
- After the correction, run the system long enough to confirm the default fault does not return under normal load.
Not sure which system this York code is on?
ACLogics has guided diagnostics for 60 York fault codes and asks the right questions to narrow it down.
