UniMac Washer-Extractor Error Code E Ub: Unbalanced Load

What does UniMac error code E Ub mean?

A washer-extractor spins its drum at high speed to remove water, and an uneven load can shake the whole machine. Before it reaches full speed, the UniMac control checks how smoothly the drum is turning through the balance switch. If the drum shakes too much, it slows down, tries to redistribute the load and tries again. When it cannot get the load to settle, it shortens the spin or skips it and shows E Ub. Heavy single pieces such as blankets, mop heads or rugs, and tangled bundles from sheets knotted together, are the usual reasons in a busy laundry. A small load of heavy items can also be the cause. The manual points to four areas to look at: how the load was packed and mixed, the balance switch and its wiring, the condition of the suspension and mounting, and whether the machine sits level. If E Ub keeps appearing on well-mixed loads of normal size, the problem is more likely the balance switch or the mounting than the laundry itself. Linens that come out wetter than usual are the direct result.

Affected models and control systems

This applies to the CHM495R family of UniMac UC-series washer-extractors, 20 to 100 lb, and to the PHM1263R family of pocket hardmount machines, models UWL, UWN and UWU 035 to 125. Both use a front-end control that posts E Ub.

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 Ub on the display after the drum slows
• The cabinet shaking or thumping during spin
• Linens coming out damper than normal
• Extract ending early

Possible causes

Listed in UniMac's documentation

• How the load was packed and mixed
• Balance switch and wiring
• Suspension and mounting condition
• Whether the machine sits level

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 balance switch that trips at normal vibration because it is out of adjustment
• Worn suspension parts or loose mounting bolts that let the cabinet move more than it should
• A washer on a floor that has settled so the frame no longer sits level

Safe checks before calling for service

How a technician diagnoses error code E Ub

1. Ask about the load types and sizes that trigger the message and whether it occurs on every cycle.
2. Check that the machine is level and that the mounting bolts or hardmount anchors are tight.
3. Inspect the suspension or mounting parts for wear, cracking or looseness.
4. Test the balance switch operation and its wiring for continuity and correct adjustment.
5. Run an evenly loaded test cycle and watch the drum through the spin ramp.

Technical reference

Document

Washer-Extractor Programming CHM495R_SVG, Part No. F8208501ENR10, March 2017, Error Codes (pp. 36-37)

Maker documentation

UniMac owner support

Edition

Part No. F8208501ENR10, March 2017

Models / control

CHM495R family washer-extractor front-end control (20-100 lb) / PHM1263R family pocket hardmount washer-extractor (UWL/UWN/UWU 035-125) front-end control

Section

Error Codes table, pp. 36-37 (E Pr only on Design 1 models; Ed01-Ed11 on Design 2 and 3 models)

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.