UniMac Washer-Extractor Error Code E Sd: Slow Drain Warning

What does UniMac error code E Sd mean?

E Sd is the slow drain message on UniMac QN, UC-series and UW pocket hardmount washer-extractors. Draining took longer than the control's average. UW machines log it in audit data, UC machines flag it during the cycle, and QN machines light the right-most decimal point on the display. It is the warning that comes before the drain alarm E dr, so it is worth acting on early.

The control keeps a running idea of how long a drain normally takes. When a drain runs slower than that, it notes the fact without stopping the batch. A floor drain or line with a partial blockage is the first cause. Lint and small items in the drain path slow the flow. The drain valve movement may be sluggish, and the level sensor response may lag.

To put out the decimal point on a QN machine, press START three times inside five seconds or cycle power.

Affected models and control systems

E Sd is listed for the CHM495R family washer-extractors (UC series, 20 to 100 lb), the PHM1263R family pocket hardmount washer-extractors (UWL, UWN and UWU 035 to 125) and the CHM1792C family QN washer-extractors, all with the front-end control.

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 right-most decimal point lights on a QN display
• The drum empties more slowly than before
• Water backs up at the floor drain
• The slow drain flag appears in UC or UW readings

Possible causes

Listed in UniMac's documentation

• Floor drain and line for a partial blockage
• Lint and small items in the drain path
• Drain valve movement
• Level sensor response

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

• Soap scum and grease narrowing a shared drain pipe
• Drain valve spring weaker so it opens slowly
• Sock or glove caught in the drain hose
• Level tube partly blocked so empty registers late

Safe checks before calling for service

How a technician diagnoses error code E Sd

1. Read the flag and the stored drain times if the control shows them.
2. Check the floor drain and building drain line.
3. Inspect the drain hose and valve passage.
4. Watch the drain valve move.
5. Check the level sensor response as the drum empties.
6. Clear or repair what slows the flow.

How error code E Sd differs from similar codes

E Sd is the early slow drain notice, while E dr is the alarm when draining runs the full drain time.

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 / CHM1792C family washer-extractor (QN models, 20-100 lb) 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.