blue-star | blue-star Error Codes: Troubleshooting, Fixes & Prevention Tips explained below.
What Does CH72 Mean?❓
CH72 indicates that the 4-way valve (also called a reversing valve) is unable to shift positions. This prevents the AC from changing between cooling and heating modes. It may be caused by a mechanical jam, solenoid coil failure, or electrical issue in the control signal.
blue-star - Causes of CH72 Error
- Faulty 4-way valve solenoid coil
- Debris or mechanical obstruction in the valve
- Incorrect refrigerant pressure preventing valve shift
- Defective control board not sending the switch signal
- Poor contact or damaged wiring in solenoid circuit
blue-star - How to Fix CH72 Error❓
Reset the Unit
- Turn off the main power supply to the AC unit.
- Wait 10 minutes, then power it back on.
Inspect the 4-Way Valve
- Check if the valve is physically jammed.
- Clean around it if debris is visible.
Check the Solenoid Coil
- Use a multimeter to test continuity.
- Replace the coil if it’s open or shorted.
Inspect Control Board Signals
- Ensure the control board is sending the correct signal to switch modes.
- Replace the board if the output is faulty.
Verify Refrigerant Pressure
- Call a technician to check system pressures.
- Fix leaks or recharge refrigerant if needed.
blue-star - Helpful Tips
- Avoid frequently switching between modes, especially in short intervals.
- Keep outdoor unit clean to prevent dust build-up on mechanical parts.
- Ensure proper voltage supply to prevent solenoid malfunction.
- Have a technician check the refrigerant annually.
- Use original replacement parts for solenoids or valve components.
Frequently Asked Questions❓
- Question: Can I still use the AC if CH72 appears?
- Answer: No. The unit may be stuck in one mode and fail to operate correctly.
- Question: Is the 4-way valve expensive to replace?
- Answer: It depends on your unit, but parts and labor can cost ₹2000–₹5000.
- Question: What happens if I ignore CH72?
- Answer: The AC may continue to run inefficiently or fail to switch modes, causing poor comfort and potential compressor strain.
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