UniMac Commercial Washer Error Code E d 29: Motor Not Connected

What does UniMac error code E d 29 mean?

When the drive prepares to run the motor, it expects to see a motor load on its three output leads. E d 29 appears when the drive finds nothing there, as though the motor were disconnected. The drive cannot turn the drum without a motor to push current through, so it stops, and the code stays until the power is cycled and the connection is restored. The most direct cause is a motor harness plug that has come unplugged, either at the motor or at the drive. A wire may be broken inside its insulation, or a motor winding may be open. The drive output stage can also fail in a way that looks like no motor. Unlike the over current codes, this one is about an absence, not a surge, so the drum and bearings are not the first suspects.

Affected models and control systems

This applies to UniMac QN washer-extractors of 20 to 100 lb, such as the UCA020QN, in the CHM1792C family with the front-end control and motor drive.

Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.

What you may notice

• E d 29 on the display
• Drum that will not turn at all
• No motor sound when the cycle should start

Possible causes

Listed in UniMac's documentation

• Motor harness plug at both ends
• Wire continuity to the motor
• Motor winding condition
• Drive output stage

Other likely causes — what usually sits behind error code E d 29 on this control. A technician confirms which one it is before any part is replaced.

• A plug that vibration has pulled partly out over months of spin cycles
• A conductor broken inside the harness where it flexes near the motor
• An open winding after the motor overheated in the past

Safe checks before calling for service

How a technician diagnoses error code E d 29

1. Ask whether any work was done recently near the motor or drive.
2. With power locked out, inspect the harness plugs at the motor and the drive.
3. Check each phase lead for continuity from the drive output to the motor.
4. Measure the motor windings for an open circuit.
5. Test the drive output stage with a known load.
6. Repair the connection or replace the part that fails.

How error code E d 29 differs from similar codes

E d 29 is about no motor being seen at all, while E d 34 is a motor that is there but does not turn.

Technical reference

Document

Washer-Extractor Programming CHM1792C_SVG, Part No. F8641001ENR4, Error Codes Table 29 (pp. 100-107)

Maker documentation

UniMac owner support

Edition

Part No. F8641001ENR4, January 2020

Models / control

CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control

Section

Error Codes, Table 29, pp. 100-108 (PDF pages equal printed pages)

Checked

October 2026

We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.