Error Code d6
Low

Ruud U96VA0702317MSA Error Code d6: Horsepower Conflict on Memory Card

TL;DR
Code d6 means the blower motor HP doesn't match what the memory card says it should be. The furnace operates normally using the IFC's internal data, but a technician should verify the motor and card are the correct parts for this model.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code d6 Mean?

A d6 code on the Ruud U96VA0702317MSA indicates a horsepower mismatch between the installed blower motor and the model data stored on the memory card at connector P6. The motor reports its HP rating to the IFC, which compares it against the HP specification on the card. When these do not match, d6 is displayed. However, the model data stored directly on the IFC microprocessor does match the installed motor, so the furnace continues to operate normally. The d6 code only appears during standby mode.

This fault most commonly follows a service call where either the blower motor was replaced with a different HP rating, or the memory card or IFC board was replaced using a part from a different model in the U96V series. Different BTU configurations within this product family use different blower motor sizes, so substituting components between models can create this HP conflict. While the furnace keeps running, the mismatch represents a parts discrepancy that should be corrected.

Running long-term with a motor HP that does not match the model specifications can cause improper airflow volumes, insufficient heat exchanger cooling, and potential damage. A technician should verify that both the installed motor and memory card are the correct parts for this specific U96VA0702317MSA model number.

Common Causes

Cause Likelihood DIY?
Blower motor or control board recently replaced with wrong part Most common ✗ Call a pro →

When to Call a Professional

Contact a licensed HVAC technician if:

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Sources

  1. Installation Instructions for (-)96V Series & (-)(-)96MDV Series

✓ Verified against manufacturer service manual — March 2026