IPSO Washer-Extractor Error Code E Ub: Out-of-Balance Stop

What does IPSO error code E Ub mean?

Heavy linen such as sheets, mats and mop heads can bunch up on one side of the drum as the water leaves. While the speed climbs during extract, the control senses whether the basket is settling into a steady turn. If the wet mass keeps pulling to one side, the control gives up on the spin and shows E Ub, protecting the machine from violent shaking. Plant staff find a soaked load and a cycle that has paused or ended. The manual's remedy is to redistribute the load and run the cycle again. A single stop after an unusual batch needs nothing more than that. Repeated stops on well-loaded batches point away from the linen and toward the machine: worn suspension, or a balance switch that misreads. At that stage the extract protection is working on information that is no longer reliable, so it should be checked.

Affected models and control systems

CHM495R washer-extractors, 20 to 100 lb, with the front-end control. Other controller generations use different codes.

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

• Extract stops early with soaked linen inside
• E Ub on the display
• Cabinet rocks or thuds as the spin builds
• One heavy lump sits to one side of the drum

Possible causes

Listed in IPSO's documentation

• Load size and weight distribution
• A single piece far heavier than the others
• Balance switch settings and suspension wear
• Drive behavior if even loads still shake the machine

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.

• Mats or blankets that absorb far more water than the rest of the batch
• A partial batch that cannot spread around the drum
• Shock absorbers losing their damping
• A balance switch that reads too early at ramp-up

Safe checks before calling for service

How a technician diagnoses error code E Ub

1. Read the code history and compare E Ub events with batch type.
2. Run a balanced test batch and observe the drum through ramp-up.
3. Inspect suspension, shock mounts and drum travel with the machine locked out.
4. Check balance switch operation and adjustment with a meter.
5. Examine drive and motor behavior if the cabinet shakes even with an even load.

Technical reference

Document

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

Edition

Part No. F8208501ENR10, March 2017

Models / control

CHM495R family washer-extractor front-end control (20-100 lb)

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.