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<h2 id="isPasted"><u>Introduction</u></h2><p>The &quot;P8&quot; and &quot;H4&quot; error codes indicate an IPM high temperature protection. 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 temperature sensor detects the IPM module temperature is too high (More than 194&#xB0;F / 90&#xB0;C).&#xA0;</p><h2 id="troubleshooting-diagram"><u>Troubleshooting Diagram</u></h2><p><img src="https://attachments.gorgias.help/Q9r0k7BYaV2vg13y/hc/9JWjXVxG8m6DvMqm/2026020315-c97fbb35-a995-4ad0-beef-b2388e874936-dyc18_troubleshooting_p8.png" style="width: 800px;" class="fr-fic fr-dib fr-bordered"></p><h2 id="troubleshooting-notes"><u>Troubleshooting Notes</u></h2><ul><li>Fasten the IPM heat sink cover plate.&#xA0;<img src="https://attachments.gorgias.help/Q9r0k7BYaV2vg13y/hc/9JWjXVxG8m6DvMqm/2026020315-24a89dae-21c9-4f06-8a6e-e466d535ce23-dyc18_troubleshooting_p8_heat_sink_cover_plate.png" style="width: 300px;" class="fr-fic fr-dib fr-bordered"></li></ul>

The "P8" and "H4" error codes indicate an IPM high temperature protection. This article is for Vertex Ducted Central Split (DYC-18) systems.

P8 & H4 Error Codes

Troubleshooting

By Error Code

Error Codes for Vertex Ducted Central Split (DYC-18) 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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Mount the Indoor Unit to the Ceiling for Quantum Ultra Floor-Ceiling Flex (UYT-24) Systems

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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

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

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

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CL error code

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P8 & H4 Error CodesUpdated 4 days ago

Introduction

Troubleshooting Diagram

Troubleshooting Notes