Ruud U96VA0702317MSA Error Code 68: No Blower Communications
What Does Code 68 Mean?
Code 68 on the Ruud U96VA0702317MSA means the Integrated Furnace Control can no longer communicate with the blower motor. This model's ECM (electronically commutated) variable-speed blower relies on a data link with the control to run; when that link breaks, the furnace shuts down.
If it happens during heating, the gas valve closes immediately, the inducer finishes its post-purge, and the furnace stops. No heating, cooling, or fan is possible until communication is restored. It is a communication failure rather than the mechanical motor failure of code 61, though a completely failed motor can cause both.
The most common cause is disconnected or damaged wiring between the control and the blower motor. Other causes include no line voltage reaching the motor, corrupted motor data on the memory card, or a failed motor. Checking these connections, the P.F.C. choke, and the motor is technician work.
What You'll Notice
- The furnace is shut down in all modes with code 68 displayed
- During a heat call the gas valve closes and the furnace stops after the inducer post-purge
- The blower never starts even though the control is otherwise powered
- The fault may follow work that disturbed the motor wiring or a memory-card issue
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Disconnected or damaged wiring between control board and blower motor | Most common | ✗ Call a pro → |
| Catastrophic motor failure | Common | ✗ Call a pro → |
How This Is Diagnosed
Because a broken communication link is usually a wiring problem, a technician checks the wiring and connectors between the control and the blower motor for damage or disconnection, and confirms line voltage is reaching the motor.
They also check the Power Factor Correction choke and the motor data on the memory card, and test the motor itself, since corrupted data or a failed motor can also break communication.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The furnace is dead in all modes and shows code 68
- The blower never starts and the furnace stops after post-purge on a heat call
- The fault appeared after work near the blower wiring or a memory-card change
Frequently Asked Questions
What is the difference between code 68 and code 61?
Code 68 means the control lost the data connection to the blower motor, while code 61 means the motor physically cannot run; both shut the furnace down but point to different repairs.
Can bad wiring alone cause code 68?
Yes — disconnected or damaged wiring between the control board and the ECM motor is the most common cause, though no line voltage, corrupted motor data, or a failed motor can also break communication.
✓ Verified against manufacturer service manual — March 2026