Wilbur Curtis G4 Brewer Message: Sensor Error
Sensor Error, shown as Open Sensor, means a break or short in the temperature thermistor circuit, and brewing stops. A technician checks the sensor resistance and wires. Resetting is done by toggling the rear switch off and on.
High: brewing stops because the brewer cannot read the tank temperature.
- Code
- Sensor Error
- Maker
- Wilbur Curtis
- Equipment
- Coffee brewers
- Applies to
- G4 ThermoPro Twin (G4 Gemini family) display message
What does Wilbur Curtis Sensor Error mean?
The brewer's tank temperature is read by a thermistor, a sensor whose resistance changes with heat. The control reads that resistance continuously. If the circuit is broken or shorted, the reading falls outside anything a working thermistor could give, and the display shows Sensor Error, with Open Sensor on screen. The manual calls it an error, and brewing stops. Its actions are to check the resistance across the sensor leads with the sensor disconnected from the UPM, where an open circuit reading means the sensor is replaced, to check the sensor wires for corrosion, and to reset by toggling the rear switch off and then on. If the error returns after the sensor and wires are good, the UPM is replaced. The numbers in the manual table did not come through in the text we could read, so we do not quote any limits.
Affected models and control systems
Wilbur Curtis G4 ThermoPro 1.5 gallon brewers, models G4TP2T (twin) and G4TP2S (single). The display shows Open Sensor for this error.
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
- Sensor Error shown as Open Sensor
- Brewing stops
- Water not heated
- Message returns after power is cycled
Possible causes
Listed in Wilbur Curtis's documentation
- Break in the temperature thermistor circuit
- Short circuit
Other likely causes — what usually sits behind Sensor Error on this control. A technician confirms which one it is before any part is replaced.
- Corroded sensor connector in the steamy area of the tank
- Sensor wire damaged near the tank
- UPM input failing so it misreads a good sensor
Safe checks before calling for service
- Switch the rear toggle off briefly and then on.
- Try one brew.
- Do not pull on wires near the tank.
- If the error returns, note whether the display says Open Sensor and call us.
How a technician diagnoses Sensor Error
- Read the display and confirm Sensor Error or Open Sensor.
- Disconnect the sensor from the UPM and measure resistance across its leads.
- Check the sensor wires for corrosion.
- Replace the sensor if the reading is open.
- Replace the UPM if the error returns.
- Resistance tests need the sensor disconnected from the UPM and a meter.
- The tank area is hot and the UPM carries line voltage.
- Choosing between sensor and UPM needs a test.
How Sensor Error differs from similar codes
Sensor Error is a break or short in the temperature circuit; Over Temp. Error is a high tank temperature.
Technical reference
- Maker documentation
- Wilbur Curtis owner support
- Edition
- F-10023; troubleshooting pages carry 122717A
- Models / control
- G4 ThermoPro Twin (G4 Gemini family) display message
- Section
- ERROR CODES, page EC1
- 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 Wilbur Curtis coffee brewer error codes
What does Open Sensor mean?
It is how Sensor Error is shown.
How do I reset?
Toggle the rear switch off and then on.
Will it return?
Yes, if the sensor or wiring is still bad. The UPM is replaced if it returns after the sensor is good.
Need help with Wilbur Curtis Sensor Error?
A technician confirms the cause on site and gives you the price in writing before any work starts.