Sensor Heater Open Error or Sensor Amplifier Error indicates a fault with the remote sensor's wiring or calibration. The manual's first action is: “Check the integrity of all sensor connections, and ensure that the cable from the S4000TH to the remote sensor is not damaged. If all sensor leads are connected properly, attempt to re-calibrate the unit. If calibration fails, replace the sensor and re-calibrate.”
- Model
- General Monitors S4000TH
- Display shows
- Sensor Heater Open Error or Sensor Amplifier Error (F4)
- Type
- Fault code
- Source
- Manual p. 38
What F4 means
Sensor Heater Open Error or Sensor Amplifier Error p. 38
Common causes
- Either one of the remote sensor leads is open or shorted, or that the sensor has drifted greater than -10% of the reading. p. 38
Safety warnings — read before you start
What to do
- Check the integrity of all sensor connections, and ensure that the cable from the S4000TH to the remote sensor is not damaged. If all sensor leads are connected properly, attempt to re-calibrate the unit. If calibration fails, replace the sensor and re-calibrate. p. 38
If F4 is still not resolved
- Contact service or dealer for assistance if the problem is not solved. p. 38 “If calibration fails, replace the sensor and re-calibrate.”
This page summarises what the manufacturer’s manual says about F4; each statement links to the page it comes from, and quoted lines are copied word for word. It is not a substitute for the manual or for a qualified installer. ManualLib is not affiliated with General Monitors. Found a mistake? Report an error.