Cooper & Hunter EHC1 error code

What it means

EHC1 means the built-in refrigerant sensor has detected a leak condition. The manual says the outdoor compressor stops and the indoor fan starts when the refrigerant sensor detects leakage.

Urgency

Likely causes

1. Cooper & Hunter Astoria R454B owner manual identifies EHC1 as refrigerant sensor detects leakage.
2. The manual states the indoor unit displays an error code and buzzes when the refrigerant sensor detects leakage.
3. The manual states the outdoor compressor stops and the indoor fan starts during refrigerant-sensor leak detection.

Homeowner fix

Do not restart cooling or heating. Ventilate the area if you suspect a leak, keep flames/sparks/smoking away, and call a licensed HVAC technician trained for R-454B/A2L equipment. Leave the unit's leak-detection safety system powered unless a technician or emergency authority tells you otherwise; the manual says units with refrigerant sensors must remain powered except for service. The remote can silence the buzzer on EHC1, but that does not make the system safe to run.

When to call a pro

Call a licensed HVAC technician immediately. Tell them Cooper & Hunter identifies EHC1 as refrigerant sensor detects leakage.

Repair vs replace

R-454B leak-detection and refrigerant-sensor faults are normally repairable by a qualified technician. Compare replacement only if the system is older, out of warranty, or the diagnosis includes multiple major components.

• Cooper & Hunter Astoria Pro 6,000 BTU R-454B 208/230V (CH-PRO06MASTWM-230VI / CH-RHP06F9-230VO)

  Astoria Pro Series

• Cooper & Hunter Astoria Pro 9,000 BTU R-454B 208/230V (CH-PRO09MASTWM-230VI / CH-RES09-230VO)

  Astoria Pro Series

• Cooper & Hunter Astoria Pro 9,000 BTU R-454B 208/230V (CH-PRO09MASTWM-230VI / CH-RHP09-230VO)

  Astoria Pro Series

• Cooper & Hunter Astoria Pro 12,000 BTU R-454B 208/230V (CH-PRO12MASTWM-230VI / CH-RES12-230VO)

  Astoria Pro Series

Parts for this line

The parts catalog for Cooper & Hunter Astoria Pro Series lists 5 sourced replacement parts for this product line.

For your technician

Technician note: treat EHC1 as active leak detection; follow A2L mitigation, inspect refrigerant circuit lines/coils/connections, confirm sensor operation, repair leak, and restore charge correctly. Page context: Cooper & Hunter maps this display to the Astoria Pro Series line; source: manufacturer documentation; display convention: match the letter E, letter H, letter C, and one marker exactly before comparing neighboring codes.

Which systems show it

Astoria Pro Series

Related troubleshooting

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

Related codes

Source

Next step