MRCOOL AC Error Codes – Causes and Solutions

MRCOOL was created after seeing a huge market gap. There was a time when heating and cooling appliances came in a single size, so regardless of the space you had to make do with one size fits all. There was no way to control heating or cooling, or even a chance to enjoy any feature. Fortunately, MRCOOL saw the gap in the market and started working on a more consumer-friendly product line.

Even to date, MRCOOL offers cutting-edge heating and cooling solutions that fit our modern lifestyle. Offering you appliances that are not only state-of-the-art but offer an advanced design and system that matches all your needs. Offering you a wide range of heating and cooling solutions that work best for your needs.

There is a time in your life when the most reliable appliance you have starts to show an error. While it might be a dark day, fortunately for you there is a simple solution for most error codes. To help you out we have accumulated a complete list of the MRCOOL air conditioner error codes. Offering you a chance to find out exactly what is wrong with your appliance, so you can finally make a decision. Rather than fighting with the appliance, or spending endless money on the repair, we suggest you first find the problem and then look for a solution.

Codes Table

How to Fix?

Error Code: E1

Trouble Case: Actuation of high pressure switch

Origin of Trouble Signal: High pressure switch

Measure: 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.

Error Code: E3

Trouble Case: Actuation of low pressure switch

Origin of Trouble Signal: Low pressure switch

Measure: 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.

Error Code: E4

Trouble Case: Air discharge high temperature protection of compressor

Origin of Trouble Signal: Exhaust over temperature protection

Measure: The exhaust temperature is higher than 125°C for more than 5sec, the system will be shut down. After stopping the compressor for 3 mins, if the exhaust temperature is lower than 90°C 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.

Error Code: F2

Trouble Case: Malfunction of condenser temperature thermistor

Origin of Trouble Signal: Condenser temperature thermistor

Measure: 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.

Error Code: F3

Trouble Case: Malfunction of outdoor ambient temperature thermistor

Origin of Trouble Signal: Outdoor ambient temperature thermistor

Measure: 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.

Error Code: F4

Trouble Case: Malfunction of Exhaust Temp. Sensor

Origin of Trouble Signal: Exhaust temperature sensor

Measure: 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.

Error Code: oN

Trouble Case: Normal operation

Origin of Trouble Signal: Unit operating normally or in standby mode.

Error Code: H1

Trouble Case: Defrost operation

Origin of Trouble Signal: Unit operating in defrost

Troubleshooting

Trouble Case: Power problem

Measure:

1. Check control transformer power (24V).
2. If power is available to demand control board and LED(s) do not light, replace control board.

Trouble Case: Actuation of high pressure switch

Measure: 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.

Trouble Case: Actuation of low pressure switch

Measure: When the unit runs more than 4 minutes or does not run, the low pressure switch opens for more than3sec 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.

Trouble Case: Air discharge high- temperature protection of compressor

Measure: The exhaust temperature is higher than 125°C for more than 5s, the system will be shut down. After stopping the compressor for 3 mins, if the exhaust temperature is lower than 90°C for more than 5s, 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.

Trouble Case: Malfunction of exhaust Temp. Sensor

Measure: If the exhaust temperature sensor is detected of open circuit 5 seconds successively after the compressor is started for 3 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.

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Danny Reese

HVAC Expert at acerrorcode.com

Regarding error and fault codes, we believe sharing knowledge is the best way to help everyone. That is why we established ACErrorCode.com, to give you every bit of info you need as a customer. HVAC Expert Contact: dannyreese@acerrorcode.com Call: 916-954-2677

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