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Error code reference

LG Hvac Error Code 22

Inverter unit high amperage.

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Inverter unit high amperage.

First step from the service manual

Verify proper 208/240V AC feeding unit, ensure unit is not operating in high-head situation, verify 3 compressor windings all equal at 1-4Ω, verify ∞Ω to ground, check amperage.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What 22 means on a LG hvac

Error code 22 on an LG inverter HVAC unit indicates a high amperage condition in the inverter compressor circuit. This fault is triggered when the compressor draws more current than the inverter drive module expects during operation. The inverter board continuously monitors compressor current, and when the draw exceeds its programmed threshold, the unit shuts down and logs code 22 to protect the compressor and power electronics from damage.

The three most common sources of this fault are power supply issues, a high-head pressure condition, or internal compressor winding problems. Insufficient or unstable voltage at the unit, particularly anything deviating significantly from the required 208/240V AC supply, forces the compressor to draw excess amperage to maintain operation. A high-head situation, such as a blocked condenser, refrigerant overcharge, or inadequate airflow, raises discharge pressure and compressor load, which directly increases amp draw. Faulty compressor windings, including partial shorts between windings or a winding-to-ground fault, will also produce abnormally high current readings.

Diagnosis begins by confirming the power supply is delivering proper 208/240V AC under load. Next, check for any condition creating elevated head pressure. The compressor windings should then be measured with an ohmmeter: all three windings should read between 1 and 4 ohms and should show infinite resistance to ground. Any deviation from these values points directly to compressor failure. If wiring and power supply check out, clamp-meter amperage readings during startup and operation should be compared against the unit's rated full-load amps to confirm whether overcurrent is actually occurring.

Source: manufacturer service documentation.

Common causes of 22

  1. 01

    Improper or low supply voltage

    Wiring / connection

    If the unit is not receiving the correct 208/240V AC at full load, the compressor compensates by pulling higher amperage. Measure voltage directly at the unit's terminal block while the system is running to confirm stable, in-spec voltage.

  2. 02

    High head pressure condition

    Wiring / connection

    Blocked condenser coils, refrigerant overcharge, or restricted airflow raises discharge pressure and forces the compressor to work harder, increasing current draw. Inspect the condenser for debris, confirm fan operation, and check system pressures.

  3. 03

    Compressor winding fault

    Part replacement

    Shorted or imbalanced compressor windings cause excessive current draw. Test all three windings with an ohmmeter: readings outside the 1 to 4 ohm range or any continuity to ground indicates a failed compressor.

  4. 04

    Refrigerant overcharge or undercharge

    Wiring / connection

    Incorrect refrigerant charge affects system pressures and compressor load, which can push amperage above normal operating limits. A manifold gauge set is needed to verify proper system charge.

  5. 05

    Failed inverter drive board

    Part replacement

    If the compressor windings and power supply both test within spec but high amperage is still present or the code returns immediately, the inverter PCB itself may be misreading current or failing to properly regulate compressor speed.

See the test procedure for each cause

Frequently asked questions about 22

What does 22 mean on a LG hvac?
Error code 22 on an LG HVAC system indicates an inverter unit high amperage fault. The system has detected that the compressor is drawing more current than the inverter drive allows and has shut down to protect the components. The fault can stem from low supply voltage, high head pressure, or a failing compressor. A technician should diagnose the root cause before restarting the system.
Can I fix error code 22 on my LG HVAC myself?
Some contributing factors, such as cleaning a blocked condenser coil or confirming the breaker and wiring are delivering proper 208/240V, are within reach of a knowledgeable DIYer. However, testing compressor windings, checking refrigerant pressures, and evaluating the inverter board all require specialized tools and training. Most repairs that address the root cause of code 22 should be handled by a licensed HVAC technician.
Is it safe to keep running my LG unit when error code 22 appears?
No. Error code 22 causes the unit to shut down specifically because continuing to operate under high amperage can damage the compressor windings, inverter board, and associated power electronics. Attempting to override or repeatedly reset the unit without fixing the underlying problem risks turning a repairable fault into a full compressor replacement.
Will resetting the unit clear error code 22?
A power reset may temporarily clear the fault and allow the unit to restart, but if the underlying cause is not corrected the code will return, often quickly. Repeated resets under a high-amperage condition can accelerate damage to the compressor and inverter components. The fault should be diagnosed and repaired rather than cleared by reset alone.
How much does it cost to repair error code 22 on an LG HVAC?
Repair cost depends heavily on the root cause. Cleaning a condenser or correcting a wiring issue is relatively inexpensive, typically in the range of $75 to $250 for a service call. Compressor replacement is the most expensive outcome, often ranging from $800 to $2,000 or more depending on unit capacity and labor rates. Inverter board replacement typically falls somewhere in between, commonly in the $400 to $900 range including parts and labor.

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