Causes and Fixes Mini Split P1 Error Code

By | June 2, 2023

How To Troubleshoot and Fix a Mini Split P1 Error Code
If a P1 error code displays on a mini split air conditioner, there are a few things a DIY type person can do before calling an HVAC tech.

Of course, if in doubt, always call a professional. Below are the most common causes and fixes for a P1 error code.

This includes Cooper and Hunter, Carrier, and many Daikin units, but be sure to check the error codes for your specific unit.

There can be a difference in errors depending on a manufacturer and model, so always verify your mini split error code with the manual for the unit.

What is a P1 Error Code on a Mini Split?

A P1 code is an Over Voltage or Low Voltage Protection.

This usually indicates there is a voltage problem with the unit.

A voltage problem includes a voltage surge (High), or under voltage (Low).

What Causes a P1 Code on a Mini Split?

  • Voltage Surge
  • Over Voltage
  • Low Voltage
  • Bad Power Supply
  • Power From Circuit Breaker Wrong
  • System Leakage or Blockage
  • Loose Connections
  • Main PCB Board

The main control board is programmed to send out a P1 code when a low or high voltage is detected.

This includes the power supply in the unit or from that circuit breaker.

Several things can cause this error with the steps below for what to check.

Steps to Troubleshoot and Fix a P1 code

  1. Check if the unit is getting the correct voltage from the circuit breaker (115-volt or 230-volt AC).
  2. Check the power wires on the outside condenser and be sure they have a good connection.
  3. Check the control wires on the inside and outside units and be sure they have a good connection.
  4. Check the power going to the main PCB board is correct.

When a mini split unit gives this error, checking to see if the correct voltage is going to the unit and main PCB needs to be done to troubleshoot a P1 code.

Check the main voltage going to the unit as well as the power supply.

Keep in mind If the power supply is bad, this can damage a PCB board.

Once the problem components are found, they must be replaced.

Category: Mini split heating and cooling air conditioner heat pump systems

About Aaron H. Benetti

Aaron H. Benetti an HVAC technician who has worked in the field since 1991. He began his career as an HVAC installer and later began doing troubleshooting and repairs. Around 2010, he began to write books on HVAC topics, mainly tutorials and how-to information. Currently, Aaron works as an HVAC tech and also writes many articles and posts for websites as well as books and videos on HVAC topics.

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