Ruud U802VA050317MSA Error Code A117_F: Detect RPM Motor Failure (Active)
What Does Code A117_F Mean?
Fault code A117_F on the Ruud U802VA is an active fault indicating a persistent blower motor RPM failure. While T117_F marks an intermittent speed observation, A117_F confirms the motor cannot maintain proper speed as an ongoing condition. The A (active) prefix means the IFC has detected this as a currently present problem rather than a historical event.
The U802VA's ECM blower motor continuously sends RPM feedback to the IFC. When the actual speed persistently deviates from the commanded target, the IFC sets A117_F. Without proper blower speed, the furnace cannot deliver the designed airflow — heating performance will be reduced, the heat exchanger may run hot, and the overall system efficiency drops significantly.
The ECM motor module — the electronics bolted to the motor body — is the most common point of failure in ECM motors with persistent RPM issues. The motor winding can also fail, but RPM issues specifically (as opposed to complete motor death) more often point to the control module. A technician must test both components separately with appropriate diagnostic tools to determine which needs replacement.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Failed blower motor or ECM module | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- Call a technician promptly — a persistent RPM failure indicates the blower motor or ECM module needs replacement before complete motor failure occurs
- A technician must determine whether the motor winding or the ECM control module is failing before ordering the replacement part
- Without correct blower speed, the furnace heat exchanger may overheat over time, causing additional damage if the motor issue is not resolved
✓ Verified against manufacturer service manual — March 2026