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<h2 id="isPasted"><u>Introduction</u></h2><p>The &quot;FA&quot; and &quot;FB&quot; error codes indicate EEPROM failure or EEPROM failure of the driver chip. This article is for <a href="https://www.pioneerminisplit.com/collections/vertex-ducted-central-split" target="_blank" rel="noopener noreferrer">Vertex Ducted Central Split (DYC-18) systems</a>.&#xA0;</p><p><strong>Cause:&#xA0;</strong>The E-side chip of the main board is faulty.&#xA0;</p><h2 id="troubleshooting-diagram"><u>Troubleshooting Diagram<img src="https://attachments.gorgias.help/Q9r0k7BYaV2vg13y/hc/9JWjXVxG8m6DvMqm/2026012918-15961bf4-ae8c-4cc8-931d-aff7f1c0008b-dyc18_troubleshooting_fa.png" style="width: 800px;" class="fr-fic fr-dib fr-bordered"></u></h2>

The "FA" and "FB" error codes indicate the chip of the outdoor unit main board is faulty. This article is for Vertex Ducted Central Split (DYC-18) systems.

FA & FB Error Codes

Troubleshooting

By Error Code

Error Codes for Vertex Ducted Central Split (DYC-18) Systems

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Prepare the Ceiling & Install the Hanging Hook for Quantum Ultra Ceiling Cassette (CYT-24) Systems

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Set Up the Indoor Unit Condensate Piping Connections for Quantum Ultra Ceiling Cassette (CYT-24) systems

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Wire the Indoor Unit & Decorative Panel for Quantum Ultra Ceiling Cassette (CYT-24) Systems

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Ducted Units

Drill the Piping Wall Hole for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

Mount the Indoor Unit to the Ceiling for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

Mount the Indoor Unit to the Floor for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

Prepare the Refrigerant Piping of the Indoor Unit for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

Select the Indoor Unit Installation Location for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

Set Up the Indoor Unit Condensate Piping Connections for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

Understand the Additional Leakage Sensor for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

Wire the Indoor Unit to the Outdoor Unit for Quantum Floor-Ceiling Flex (UYT-24) Systems

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Flex Units

Connect the Drain Hose for Quantum Fresh (WYT-FA) Systems

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CL error code

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FA & FB Error CodesUpdated 4 days ago

Introduction

Troubleshooting Diagram