ACiQ EHC1 error code

What it means

EHC1 is a refrigerant leak alarm from the indoor refrigerant sensor. Because the system uses R-454B A2L refrigerant, treat this as a stop-use safety event.

Urgency

Likely causes

1. Actual refrigerant leak at a flare joint, coil, line set, or service connection
2. Low refrigerant charge or charge loss after installation or service
3. Refrigerant sensor, T1/T2, or related control input reading abnormally
4. Indoor or outdoor board fault only after the leak and sensor checks pass

Homeowner fix

Turn the system off, ventilate the space, avoid flames, sparks, and smoking, and do not reset the unit back into normal operation. Expected result: the system stays off until a licensed technician verifies the leak sensor and refrigerant circuit.

When to call a pro

Call a licensed HVAC technician immediately. Tell them the display is EHC1 and the manual says the refrigerant sensor detected leakage.

Repair vs replace

A leak-sensor replacement or minor leak repair may be reasonable, especially under warranty. If the repair involves a coil, buried line set, or repeated refrigerant loss, compare the quote with replacement.

• ACiQ Multi-Zone Extreme Series 2-Zone 18,000 BTU R-454B 208/230V (ACIQ-18Z-HH-M3C)

  Multi-Zone Extreme Series

• ACiQ Multi-Zone Extreme Series 3-Zone 27,000 BTU R-454B 208/230V (ACIQ-27Z-HH-M4C)

  Multi-Zone Extreme Series

• ACiQ Multi-Zone Extreme Series 4-Zone 36,000 BTU R-454B 208/230V (ACIQ-36Z-HH-M5C)

  Multi-Zone Extreme Series

• ACiQ Multi-Zone Extreme Series 5-Zone 48,000 BTU R-454B 208/230V (ACIQ-48Z-HH-M6C)

  Multi-Zone Extreme Series

For your technician

Technician note: follow R-454B/A2L leak-safety procedures, ventilate and verify the area, locate any leak, repair before recharge, and verify the sensor. Page context: ACiQ maps this display to the Multi-Zone Extreme Series line; source: ACiQ Multi-Zone Service Manual and shared Midea D5CMRA Table 20 display reference; display convention: match the letter E, letter H, letter C, and one marker exactly before comparing neighboring codes.

Which systems show it

• ACiQ Multi-Zone Extreme Series R-454B systems using the shared Midea/ACiQ multi-zone platform.
• ACiQ Multi-Zone Standard Series R-454B systems where the ACiQ service manual lists the same EC/EH/EL/PC diagnostics.
• ACiQ wall-mounted, cassette, duct, console, and AHU indoor units listed in service manual section 7.2.

Sold under more than one brand

Shared with Midea. ACiQ and Midea document this code from the same manufacturer source, so EHC1 means the same thing on either badge and the steps above apply.

Related troubleshooting

Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.

Reset note

Turn the system off, ventilate the space, avoid flames, sparks, and smoking, and do not reset the unit back into normal operation. Expected result: the system stays off until a licensed technician verifies the leak sensor and refrigerant circuit.

Manual trigger

EHC1 is a refrigerant leak alarm from the indoor refrigerant sensor. Because the system uses R-454B A2L refrigerant, treat this as a stop-use safety event.

Related codes

Source

Next step