Cooper & Hunter EHC3 error code

What it means

EHC3 means the refrigerant sensor is operating outside its expected range. Even without the manual's leak-detected wording, the leak-detection safety system cannot be trusted until serviced.

Urgency

Likely causes

1. Cooper & Hunter Astoria R454B owner manual identifies EHC3 as working condition of the refrigerant sensor is out of range.
2. The manual states EHC3 applies only to units with refrigerant sensors.
3. The manual states a malfunctioning refrigerant sensor cannot be repaired and must be replaced with the manufacturer-specified sensor.

Homeowner fix

Do not restart cooling or heating. Keep ignition sources away if you suspect a leak and call a licensed HVAC technician trained for R-454B/A2L equipment. Leave the unit's leak-detection safety system powered unless service or emergency personnel tell you otherwise.

When to call a pro

Call a licensed HVAC technician. Tell them Cooper & Hunter identifies EHC3 as refrigerant sensor working condition out of range.

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: verify refrigerant sensor environment, wiring, connector, and controller input; replace only with the manufacturer-specified sensor if the sensor has failed. 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 three 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