If you’re looking for help fixing your MrCool furnace, look no further! Our comprehensive MrCool furnace repair guide will explain common issues, provide troubleshooting tips, and show you how to read your model’s error codes.

CODE: E1.
PROBLEM: Actuation of high pressure switch.
FIX: Abnormality is detected when the contact of the high pressure switch opens for 3 sec. The system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.

CODE: E3.
PROBLEM: Actuation of low pressure switch.
FIX: When the unit runs more than 4 minutes or does not run, the low pressure switch opens for more than 3sec and the system will be shut down. The unit will report this fault. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.

CODE: E4.
PROBLEM: Air discharge high temperature protection of compressor.
FIX: The exhaust temperature is higher than 125C for more than 5sec, the system will be shut down. After stopping the compressor for 3 mins, if the exhaust temperature is lower than 90C for more than 5 sec, the compressor will re-start. For the first two faults within 30 minutes, the unit can be recovered automatically. If over three times, the unit cannot be recovered automatically.

CODE: F2.
PROBLEM: Malfunction of condenser temperature thermistor.
FIX: Malfunction of condenser temperature thermistor is detected when there is a short circuit or an open circuit in the condenser temperature thermistor for more than 5 sec. The system will be shut down. The reset for the malfunction of condenser temperature thermistor is automatic.

CODE: F3.
PROBLEM: Malfunction of outdoor ambient temperature thermistor.
FIX: Malfunction outdoor ambient temperature thermistor is detected when there is a short circuit or an open circuit in the outdoor ambient temperature thermistor for more than 5 sec. The system will be shut down. The reset for the malfunction of condenser temperature thermistor is automatic.

CODE: F4.
PROBLEM: Malfunction of Exhaust Temp. Sensor.
FIX: If the exhaust temperature sensor is detected of open circuit 5 seconds successively after the compressor is started for 2 minutes or short circuit 5 seconds successively at any time . The system will be shut down. After the fault is eliminated, the system can automatically resume to operation.

CODE: ON.
PROBLEM: Normal operation.
FIX: Unit operating normally or in standby mode.

mrcool furnace codes

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