How to Replace a MRCOOL Mini Split Air Handler

Replacing your MRCOOL air handler can be straightforward if you follow the proper steps. Whether you have a DIY model or a professional system, use the guide below to ensure a safe and smooth process.

Before You Begin

• DIY Systems (with pre-charged line sets): If your system is a true DIY model, you can disconnect the pre-charged line sets from your current air handler and reconnect them to the new one.

• Non-DIY Systems: If your system is not DIY, you’ll need a licensed HVAC technician to complete the replacement. This ensures refrigerant is handled properly and the system is charged to the correct levels.

Step 1: Power Down the System

• Turn off power to the unit at the breaker and confirm it is off with the use of a voltmeter to avoid electrical hazards.

Step 2: Remove the Air Handler from the Mounting Bracket

1. Disengage from the Mounting Bracket:

   • At the bottom of the air handler, near the wall, locate the two lifting tabs.

   • Insert your fingers into the tabs, gently lift the unit upward, and pull it forward.

   • This will release the air handler from the wall bracket.

Step 3: Disconnect Line Sets and Wiring

• DIY Systems: Carefully disconnect the pre-charged line sets and electrical connections. Be mindful not to bend or damage the lines.

  • shutoff the line set connections by closing the valves at the condenser 

• Non-DIY Systems: Stop here and have a licensed technician disconnect the refrigerant lines and wiring.

Step 4: Install the New Air Handler

1. Mount the Unit:

   • Place the new air handler onto the mounting bracket, aligning it properly.

   • Lower it gently into place until it locks onto the bracket.

2. Reconnect Line Sets and Wiring:

   • For DIY systems, reconnect the pre-charged line sets and electrical wiring.

   • Leak-check all connections to ensure they’re tight and secure.

Step 5: Test the System

• Restore power at the breaker.

• Turn the unit on and check for proper operation.

• Listen for unusual noises and check that airflow is consistent.

Additional Tips

• Keep all screws and parts organized during the process.

• If you encounter resistance when removing the unit, check for any missed screws or obstructions.

• When in doubt, consult a licensed HVAC professional for assistance.

Refrigerant Leak Disclaimer

If a refrigerant leak is present in the mini-split system, simply adding refrigerant will not resolve the issue. The source of the leak must first be identified and the leaking component or connection must be properly repaired or replaced. Once the repair has been completed, the system must be evacuated by pulling a vacuum to remove air, moisture, and contaminants from the refrigerant lines and components. After a proper vacuum has been verified, the system can then be recharged with the correct type and amount of refrigerant according to manufacturer specifications. Failure to repair the leak and properly evacuate the system before recharging may result in poor performance, equipment damage, and continued refrigerant loss.