Speed Queen Washer Error Code E Ub: Unbalance Error

What does Speed Queen error code E Ub mean?

Before a high-speed extract, the control tries to even out the load by turning the drum and watching how the machine reacts. If it cannot get the load to balance, it stops the spin to protect the machine and shows E Ub. The wash is done, but the extract step is not, so you find a wet load sitting in the drum. Heavy items piled on one side of the drum are the usual reason. Rugs, bedding and other items wound together make a single mass that cannot spread out. When a well-spread load still triggers the code, the cause is likely in the machine: suspension and shock mounts that no longer hold the drum steady, or drum or bearing wear that lets it wobble. The control cannot say which, only that balancing failed. On a Quantum frontload and a CHM495R washer-extractor, the same code is raised by the same check.

Affected models and control systems

This page covers Quantum frontload washers in the FLW1535C family and CHM495R washer-extractors, 20 to 100 pounds. The CHM495R also has a separate frame balance switch with its own code.

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

• The spin never reaches full speed
• The load stays wet in the drum
• E Ub appears after the wash

Possible causes

Listed in Speed Queen's documentation

• Load size and how it is distributed
• Items like rugs or bedding wound together
• Suspension and shock mounts
• Drum or bearing wear

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

• A single heavy item that soaked up water and sits like a weight at the bottom of the drum
• Shock mounts that have lost their damping after years of heavy loads

Safe checks before calling for service

How a technician diagnoses error code E Ub

1. Read the code and ask about load size and the items in it.
2. Run a short test spin with a balanced load and watch how the drum moves.
3. Inspect the suspension and shock mounts for wear or leaking dampers.
4. Check the drum for play at the bearing with power off.
5. Replace the worn mounts or bearing only after the play and movement are confirmed.

Technical reference

Document

Commercial Frontload Washers Troubleshooting FLW1535C, Part No. 803402R2, March 2016, Section 4 Table 3 (pp. 18-20)

Edition

Part No. 803402R2, March 2016

Models / control

Quantum frontload (FLW1535C family) electronic control; CHM495R family washer-extractor front-end control (20-100 lb)

Section

Section 4 Electronic Control Troubleshooting - 8. Error Code Listing, Table 3, printed pp. 18-20 (PDF pp. 20-22)

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.