⚠️ What Causes Error Codes on Different Aircon Brands?

When your aircon suddenly shows an error code, it’s the system’s way of telling you something is wrong. Different brands use different codes, but most of them point to similar problems inside the system.

Error codes should never be ignored. They help identify faults early, prevent breakdowns, and protect major parts like compressors and fan motors.

Here are the most common causes behind aircon error codes in Singapore homes.

1. Communication Fault Between Indoor & Outdoor Unit

Most modern aircons have two-way communication between the indoor unit and outdoor condenser. When the signal is interrupted, an error code appears.

Common causes:

• Loose wiring

• Faulty control board

• Damaged communication cable

• Water damage inside the indoor unit

Brand examples:

• Daikin: U4

• Mitsubishi Electric: P8

• Panasonic: H11

Solution: A technician must check wiring connections and the PCB board.

2. Refrigerant (Gas) Issues

Low gas levels, pressure imbalance, or leaks can trigger protection codes.

Signs:

• Weak cooling

• Ice forming on pipes

• Random warm air

Typical codes:

• Daikin: E3 (low pressure)

• Mitsubishi Electric: P6

• Panasonic: H27

Solution: Leak check + proper gas top up.

3. Fan or Motor Malfunction

When the indoor or outdoor fan fails, the aircon cannot operate safely. Brands show different errors, but meaning is similar.

Examples:

• Daikin: U7 (indoor fan)

• Mitsubishi Electric: F9

• Panasonic: H19

Causes:

• Dust buildup

• Worn motor

• Faulty capacitor

4. Overheating of Compressor or Outdoor Unit

If your condenser overheats, the aircon switches into protection mode and shows an error.

Causes:

• Dirty outdoor coil

• Blocked ventilation

• Weak fan motor

Codes may include:

• Daikin: A5

• Panasonic: H00 or H90

5. Drainage or Water Sensor Problems

When water cannot drain properly, the system prevents operation to avoid leaks.

Causes:

• Blocked drain pipe

• Faulty drainage sensor

• Mould buildup

Common codes:

• Daikin: A3

• Panasonic: H23

• Mitsubishi Electric: P15

6. PCB or Electrical Fault

This is one of the most serious causes of error codes.

Symptoms:

• Aircon switches off

• Display flashes

• Burning smell

• No response from remote

Reason: Faulty circuit board, short circuit, capacitor damage.

Codes:

• Daikin: A1

• Panasonic: H16

• Mitsubishi Electric: U0

7. Temperature or Sensor Failure

If the sensor cannot read accurate temperatures, the aircon stops cooling for safety.

Typical issues:

• Loose sensor

• Sensor touching coil

• Damaged wiring

Codes:

• Daikin: A6

• Panasonic: H14

• Mitsubishi Electric: P4

How Sky Blue Aircon Fixes Error Codes

At Sky Blue Aircon Engineering Pte Ltd, we diagnose error codes across all major brands quickly and accurately.

Our services include:

• Error code troubleshooting

• PCB and sensor testing

• Drainage and coil cleaning

• Leak checks and gas top up

• Fan, motor and capacitor repair

• Wiring and communication fault checks

We make sure your system runs safely and reliably.

💡 The Bottom Line

Error codes are not random. They are early warning signs telling you something needs attention. Fixing them early prevents major breakdowns and protects your compressor.

📲 Message us on WhatsApp at 9248 7291 or call 6556 4042.

Sky Blue Aircon Engineering Pte Ltd keeping Singapore homes cool, protected, and trouble-free.