White Westinghouse Air Conditioner Error P4

⚡ Quick Answer: The P4 error on a White Westinghouse Air Conditioner indicates an overload protection issue with the inverter compressor. This may result in the unit ... ⚠️ Difficulty Varies

What Does Error P4 Mean?

The P4 error on a White Westinghouse Air Conditioner indicates an overload protection issue with the inverter compressor. This may result in the unit failing to cool, often accompanied by unusual humming sounds. It typically occurs due to faults in the inverter drive, voltage supply instability, or issues with the control electronics. If you see this error, it's essential to address potential problems quickly to avoid further damage.

Common Symptoms:

  • Unit stops cooling or shuts down with P4 displayed on control panel (common for P4 in many HVAC systems)
  • Inverter/compressor related faults leading to protection shutdown
  • May show alongside reduced operation or protection mode

Possible Causes

  • Inverter compressor drive fault (medium)
  • Voltage protection trigger or unstable supply causing inverter fault (medium)
  • Sensor/board/related control electronics issue leading to inverter protection (medium)

How to Fix Error P4

DIY Fix Basic Checks and Reset

  1. Turn off the air conditioner at the main power switch or breaker.
  2. Wait several minutes then restore power to attempt a soft reset of error codes.
  3. Ensure the air filter is clean and not heavily blocked.
  4. Check the power outlet/circuit for obvious issues (loose plug, tripped breaker).

Technician Only Technical Diagnosis and Repair

  1. Inspect the outdoor inverter compressor drive circuitry and related sensors for damage or error codes.
  2. Check and stabilize the power supply to the unit (ensure adequate voltage and no large fluctuations).
  3. Measure and test inverter board components, including capacitors and IPM modules.
  4. Verify wiring and connections between indoor and outdoor units, especially around the inverter and compressor.
  5. Replace defective parts as needed (inverter board, sensors, compressor drive components).

Parts needed: Inverter control board / drive module, Voltage supply components (fuses, surge protection), Compressor drive sensors/electronics

🛑 When to Call a Pro:
  • If basic reset and filter cleaning do not clear the error
  • If P4 returns immediately after power cycling
  • If you are uncomfortable working near electrical components

Next step

Choose the next step for P4

Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.

Based on diagnostic data

Most relevant component to inspect

HVAC Control Board

Controls fan, compressor, sensor, and communication functions in the HVAC unit.

Typical part-only price
$90 - $320
DIY difficulty
Hard
Estimated time
45-120 mins
Where can I find the model number?

Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.

Find a part that fits my model

Verify the complete model and part number on the retailer's compatibility page before ordering.

Other components that may be involved

Check these only if your diagnosis points to them.

Possible related component

Compressor

Compresses refrigerant within the sealed cooling system and requires specialized service equipment.

$180 - $600 · Hard · 120-240 mins

Professional diagnosis

Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. We may earn a commission from other qualifying purchases or service requests made through links on this page, at no additional cost to you. Recommendations are based on repair relevance, not commission rate.

Technical Specifications

wattage 1500W
component Compressor
resistance 5-10 ohms
part_number WAC-123456
voltage_rating 115V AC

Common Questions

What does P4 error mean on White Westinghouse Air Conditioner?

P4 indicates an overload protection issue with the inverter compressor, leading to cooling failure.

Can I fix White Westinghouse Air Conditioner P4 error myself?

Yes, you can try basic checks like resetting the unit and cleaning the air filter.

How much does it cost to fix P4 error?

Repair costs range from ¥20,000 to ¥80,000+, depending on parts and labor.

When should I call a technician for P4?

Call a technician if the error persists after a reset or if you're uncomfortable with electrical components.

Data last verified: 2026-04-23

User Comments (0)

Share your experience or solution below.

Be the first to comment!