Speed Queen Washer Error Code E oP: Open Temperature Sensor
E oP reports an open temperature sensor circuit on heater models. The heater turns off and the cycle continues, so the wash may finish with cooler water than selected. Open the door or press a key to clear it, and call us if it returns.
Medium: the cycle continues but the heater is off, so the water may be cooler than selected.
- Code
- E oP
- Maker
- Speed Queen
- Equipment
- Washers
- Applies to
- Quantum frontload (FLW1535C family) electronic control; Stacked washer/dryer (SWD447C) washer electronic control; CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control; CHM495R family washer-extractor front-end control (20-100 lb)
What does Speed Queen error code E oP mean?
Heater models read the water temperature with a thermistor, a small sensor whose resistance changes with heat. If the wire or the sensor itself breaks, the circuit goes open and the control sees an impossible reading. On the CHM495R that reading is a temperature below 0 degrees Fahrenheit, which tells the control the thermistor circuit is open. With no trustworthy temperature, the control shuts the heater off and shows E oP. The cycle goes on, so the wash may end with water cooler than the formula called for. That is why the code can slip by unnoticed. The sensor plug and wiring, the thermistor itself, or the control input that reads it are the usual places to look, and the machine has to be a heater model for the code to apply. It appears on Quantum frontload washers, the older stacked washer/dryer where it is written E:OP, and on CHM1792C and CHM495R washer-extractors.
Affected models and control systems
This page covers heater models of the Quantum frontload (FLW1535C family), the washer side of the SWD447C stacked washer/dryer, and CHM1792C and CHM495R washer-extractors. A shorted sensor reports E SH instead.
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
- Wash water comes out cooler than selected
- E oP appears but the cycle completes
- The heater never turns on
Possible causes
Listed in Speed Queen's documentation
- Thermistor plug and wiring
- Thermistor itself
- Control input reading the sensor
- Whether the machine is a heater model
Other likely causes — what usually sits behind error code E oP on this control. A technician confirms which one it is before any part is replaced.
- A thermistor lead that has fatigued and broken inside its insulation after years of vibration
- A sensor plug corroded by steam so the circuit reads open
Safe checks before calling for service
- Open the door or press any keypad to clear the code, as the owner's manual says for the CHM1792C.
- Let the cycle finish, then feel whether the water was warm.
- Leave heater wiring and panels alone.
- If E oP returns, note the formula and temperature you selected, and reach out so we can set up a visit.
How a technician diagnoses error code E oP
- Read the code and confirm the machine is a heater model.
- Measure the thermistor resistance at the sensor and compare it with the chart for the water temperature.
- Inspect the plug and the wire run for breaks, corrosion or pinching.
- Check the control input by substituting a known resistance.
- Replace the thermistor or wiring only after the open circuit is found.
- The sensor sits near the water and the heater, where steam and line-voltage heater wiring share the cabinet.
- Resistance and input checks need the machine's temperature chart and a calibrated meter.
- Confirming that the heater still switches off safely means working with the control energized.
How error code E oP differs from similar codes
E SH reports the opposite condition on this sensor circuit, a short instead of an open.
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; Stacked washer/dryer (SWD447C) washer electronic control; CHM1792C family washer-extractor (QN models, 20-100 lb) front-end 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.
Related Speed Queen washer error codes
Why is the water cooler than I set?
With the sensor reading wrong, the control turns the heater off, so the water stays at the supply temperature.
Can I keep washing?
The washer will run, but loads that need heat may not get it.
Is E oP the same as E SH?
No. E oP is an open sensor circuit; E SH is a shorted one.
Need help with Speed Queen error code E oP?
A technician confirms the cause on site and gives you the price in writing before any work starts.