IPSO Washer-Extractor Error Code E oP: Open Temperature Sensor
E oP on an IPSO CHM495R washer-extractor means the temperature sensor circuit reads open, as if the sensor were disconnected or broken. The manual puts the reading below 0 F, so the control cannot trust the sensor; note whether the water comes out cooler than programmed.
Medium: temperature control is lost, so washes may be cooler than programmed.
What does IPSO error code E oP mean?
The wash temperature is measured by a sensor whose resistance changes with the water temperature. The control converts that into a reading. When the circuit is open, because the sensor is unplugged or broken or a wire has snapped, the control sees a value below 0 F, which water in a washer could never reach. It concludes the sensor cannot be trusted and displays E oP. Heated machines lose their temperature control, so staff see washes that come out cooler than programmed. If the cycle carries on, the washing itself may continue, but the heat is not regulated. A temperature sensor unplugged at its connector or broken is the first thing to look for. A broken wire between the sensor and the control comes next, then a heater that also fails to draw current, and finally a failed sensor input on the control. The opposite case, a shorted sensor, appears as E SH.
Affected models and control systems
This applies to IPSO washer-extractors in the CHM495R family, 20 to 100 lb, with the front-end control in that programming manual.
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 oP appears and the water comes out cooler than programmed
- The heater does not seem to run
- The cycle may carry on without temperature control
Possible causes
Listed in IPSO's documentation
- Temperature sensor unplugged at its connector or broken
- Broken wire between the sensor and the control
- Heater that also fails to draw current
- Failed sensor input on the CHM495R control
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 sensor connector pulled loose when the machine was moved for floor cleaning
- A sensor wire cracked where it flexes near the tub
Safe checks before calling for service
- Note whether the wash water comes out cooler than the cycle calls for.
- Keep clear of the sensor and its wires.
- If the cycle carries on, let it run to the end.
- Ask us to test the sensor if E oP returns, and tell us which cycle was running.
How a technician diagnoses error code E oP
- Read the code and confirm E oP returns after a power cycle.
- With the power locked off, check the sensor connector for a loose or corroded fit.
- Measure the sensor resistance and compare it with the expected value at room temperature.
- Check the wire between the sensor and the control for continuity.
- Test the control's sensor input with a known resistor before replacing the sensor or the control.
- The sensor sits in the tub near the heater and live wiring, so reaching it means opening panels.
- Reading resistance accurately and comparing it with the temperature requires a meter and the sensor chart.
- If the heater also draws no current, the problem may involve contactor and element circuits at 208 to 240 V.
How error code E oP differs from similar codes
E oP is a sensor circuit that reads open. E SH is one that reads shorted, and E Ht is the heat time running out.
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.
Related IPSO washer error codes
Does E oP mean the water is below 0 F?
No. The control reads that value because the circuit is open.
Can I keep washing?
The cycle may carry on, but the heat is not controlled.
Will it clear by itself?
Only if a connector was briefly loose. A broken sensor or wire stays broken.
Need help with IPSO error code E oP?
A technician confirms the cause on site and gives you the price in writing before any work starts.