UniMac QN Washer-Extractor Error Code E Hd: Water Too Hot to Drain

What does UniMac error code E Hd mean?

E Hd is the too hot to drain error on a UniMac QN washer-extractor such as the UCA020QN, shown when the option is enabled. The option exists to protect drain lines from very hot water. When it is on, the control checks the water temperature before it opens the drain. If the water is hotter than the allowed limit, the control holds the drain closed and shows the code.

Pressing any key clears the display. The cycle then waits for the water to cool before the drain opens, so the batch is delayed rather than lost. In most cases the water is simply still too hot to drain. A temperature sensor that reads higher than the real water temperature can hold the drain closed too long. A cool-down setting may keep the drain closed for a long time. A hot supply set so high that the tub fills with very hot water makes the code frequent.

Do not touch the door until the water has cooled.

Affected models and control systems

E Hd is listed for the CHM1792C family washer-extractors, the QN models from 20 to 100 lb, with the front-end control; the manual's example model is the UCA020QN.

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 display shows E Hd after a hot wash step
• The drum stays full while the cycle waits
• The cabinet and door feel warm
• The wait is longer after hot cycles

Possible causes

Listed in UniMac's documentation

• Water in the drum that is simply still too hot to drain
• A temperature sensor that reads higher than the real water temperature
• A cool-down setting that holds the drain closed for a long time
• A hot supply set so high that the tub fills with very hot water

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

• Boiler or water heater setpoint raised during a seasonal adjustment
• Temperature sensor with scale on its tip that reads high
• Cool-down program entered for a different fabric type
• Hot line blended poorly, so the tub fills near the maximum

Safe checks before calling for service

How a technician diagnoses error code E Hd

1. Read the code and confirm the option is enabled.
2. Check the hot supply temperature at the machine.
3. Compare the sensor reading with a thermometer on the drum water.
4. Review the drain-hot setting and cool-down time with the owner.
5. Clean or replace the sensor if its reading is wrong.

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.