Newco Coffee Brewer Error Code E1: Open Thermistor
E1 means the brewer found extremely high resistance from the lower thermistor, which the manual calls an open thermistor. It resets itself once the condition clears. The manual says to check or replace the thermistor and to power the unit off and on to reset.
High: the brewer cannot read water temperature and will not heat or brew normally.
- Code
- E1
- Maker
- Newco
- Equipment
- Coffee brewers
- Applies to
- Newco 20:1-LD, 20:1-AP, 20:1-TD, 20:1-LP3, 20:1-AP Pro, thermal models
What does Newco error code E1 mean?
A Newco 20:1 brewer keeps its water at brewing temperature by reading a thermistor, a small sensor whose resistance changes with temperature. The control expects a resistance within a normal range. If the circuit shows extremely high resistance, as an open wire or a failed sensor would, the control cannot read a temperature and displays E1 (Open Thermistor). The manual ties the high resistance to the lower thermistor and adds that the upper thermistor is also bad. It says the error auto-resets once the condition clears, so the display may return to normal after a loose connection is restored or the reading comes back. The actions listed are to check or replace the thermistor, and to power the unit off and on to reset. Since the brewer cannot tell how hot the water is, it will not keep heating normally while E1 is active.
Affected models and control systems
Newco 20:1-LD, 20:1-AP, 20:1-TD, 20:1-LP3, 20:1-AP Pro and thermal models.
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
- E1 (Open Thermistor) shown on the brewer display
- Water not heating to brewing temperature
- Brew cycle blocked or not starting
- The error disappearing and returning
Possible causes
Listed in Newco's documentation
- Resistance extremely high from lower thermistor; upper thermistor is also bad
Other likely causes — what usually sits behind error code E1 on this control. A technician confirms which one it is before any part is replaced.
- Thermistor connector pulled loose from the control board
- Lead broken inside its sleeve near the tank
- Thermistor element failed open from age or scale
- Moisture in the thermistor plug
Safe checks before calling for service
- Switch the brewer off with its power switch and unplug it for a minute.
- Plug it back in, switch it on and watch whether E1 returns, as the manual says to power off and on.
- Check that the brewer is level and that nothing has been spilled onto the back or base.
- If E1 returns, stop using the brewer and call for service.
- Tell the technician whether E1 appeared at startup or during a brew, and whether it cleared by itself.
How a technician diagnoses error code E1
- Read the display and confirm E1 and its history.
- Check the thermistor wiring and plug for a loose or damaged connection.
- With power off, measure the thermistor resistance and compare it with its temperature table.
- Check the upper thermistor as well, since the manual says it is also bad.
- Replace the thermistor that fails, then confirm water temperature rises normally.
- The thermistors are in the hot water tank, which holds scalding water and live heater wiring.
- Resistance values must be compared with a meter against the right temperature table.
- A brewer that cannot read temperature must be tested before the heater is allowed to run.
How error code E1 differs from similar codes
E2 is the shorted-thermistor version of the same sensor circuit, with extremely low resistance instead of high.
Technical reference
- Document
- 20:1 Coffee/Tea Brewer Operation and Service Manual
- Edition
- Man PN 121751 Rev 20260710
- Models / control
- Newco 20:1-LD, 20:1-AP, 20:1-TD, 20:1-LP3, 20:1-AP Pro, thermal models
- Section
- Error Messages, p. 6
- 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 Newco coffee brewer error codes
Will E1 clear on its own?
The manual says it auto-resets once the condition clears, so a restored connection can clear it.
Is E1 the same as E2?
No. E1 is high resistance (open). E2 is low resistance (shorted).
Can I keep brewing with E1?
The brewer cannot read water temperature, so it should not be used until it has been checked.
Need help with Newco error code E1?
A technician confirms the cause on site and gives you the price in writing before any work starts.