U-Line Ice Maker Code E2 Explained: Thermistor 2 Reads Open
E2 on a U-Line ice machine says its second temperature sensor reads open. With no signal from Thermistor 2, the control cannot follow part of the cycle, and less ice is made.
What does U-Line ice machine code E2 mean?
A U-Line UONB115, UHNP315 or UCLR1215 puts E2 on the display when its second temperature sensor, Thermistor 2, is open. The control hears nothing from that sensor and has no way to judge the part of the ice-making cycle that depends on it, so output falls off. If the same sensor were shorted instead, the display would read E6. Which of the two appears tells us what the control found.
E2 at a glance
- Code
- E2
- Appliance
- U-Line ice machine
- Applies to
- U-Line UONB115, UHNP315 and UCLR1215 units
- Type
- Needs attention soon
- Can you clear it yourself?
- Sometimes, after the safe checks below
- Most likely cause
- Thermistor 2 has gone open inside the cabinet
What you may notice with E2
- E2 shows on the display of the ice machine.
- Ice output drops compared with normal.
- The bin takes much longer to fill.
- Nothing leaks, and the machine otherwise seems to run.
How the ice machine detects E2
Several temperature sensors, called thermistors, are fitted to a U-Line ice machine, and each one tells the control about a different part of the cycle. Thermistor 2 is the second. The control sends a tiny current through it and measures how much resistance comes back, which converts to a temperature.
If that circuit is open, nothing comes back at all, and the control treats this as a failed reading and posts E2. The control can no longer judge the stage that depends on this sensor, so it slows ice making, and output drops. An open circuit may start at the sensor itself, at the wire along its path or at a loose connector, and it sits behind panels where it cannot be seen from outside. Testing the path with a meter tells us which part to fix before anything is ordered.
Likely causes of E2
- Thermistor 2 has gone open inside the cabinet
- A lead to the second sensor is broken, or its connector is loose
- The control input for that sensor is not registering a signal
Can you keep using the ice machine with E2?
You can keep the machine plugged in while you arrange a repair, but expect little ice. E2 is a sensor reading problem and not a danger in itself. Do not remove covers to look for the cause, because the break sits behind panels. If water appears on the floor, treat that as a separate problem and switch the machine off.
What you can safely check
- Turn the machine off for a minute so nothing is running when you look around it.
- Switch it on again and see whether E2 returns.
- Clear dust and objects away from the cabinet.
- Confirm the bin door shuts tight.
- Leave the covers on.
- If E2 is still there after the restart, we can arrange a visit.
What our technician does for E2
- Measure Thermistor 2 for an open circuit
- Inspect the sensor lead and plug for a break or a loose fit
- Test the board input for the second sensor
- Replace the part that tested bad
How to keep E2 from coming back
- Keep boxes and supplies away from the cabinet so air can circulate.
- Do not let anything press against wiring when sliding the machine in and out.
- Wipe up spills near the cabinet quickly, since moisture can reach connectors over time.
Technical reference
- Code
- E2
- Appliance
- U-Line ice machine
- Control family
- U-Line UONB115, UHNP315 and UCLR1215 units
- Maker documentation
- U-Line owner manuals and support
- Checked
- November 2026
Code meanings come from the maker’s documentation and our own repair work; we do not reprint the maker’s document. Confirm the full model number before acting on a code. We are an independent repair company, not affiliated with U-Line Corporation.
Related U-Line ice machine error codes
E2 questions
What is the second sensor in E2 doing?
Thermistor 2 is a temperature sensor the control relies on for one stage of the ice-making cycle. When it reads open, that stage runs without a temperature and the cycle suffers.
Is a leak behind E2?
No. This code comes from a temperature sensor circuit, not from water. Should you also find water on the floor, treat it as its own problem, and both can be looked at in a single visit.
How are E2 and E6 connected?
E6 stands for the second sensor reading shorted. The two codes are the open and shorted forms of one sensor, so the same circuit gets tested whichever code you see.
Will E2 clear by itself?
It may disappear after a restart if the connector settled back into place, but a real open sensor brings the code back. If E2 returns, the circuit needs testing so the true cause can be found and fixed.
Does a warranty cover an E2 repair?
That depends on your terms, so check your warranty terms before work begins. Have the model and the code ready, because the maker may ask for both when you check.
Need help with E2?
A technician finds the cause at your bar or lanai and puts the price in writing before any part comes out.