U-Line E8 Ice Machine Code: Thermistor 4 Shorted
E8 on a U-Line UONB115 or UHNP315 ice machine means Thermistor 4 is shorted. The reading is invalid, so the ice cycle slows until the sensor circuit is repaired.
What does U-Line ice machine code E8 mean?
E8 comes up on the UONB115 and UHNP315 ice machines from U-Line when Thermistor 4 is shorted. The fourth temperature sensor looks like a direct connection to the control, so what it reports is not a believable temperature. Clear ice machines like the UCLR1215 do not have E8 in their table. The ice cycle slows while E8 is showing. When the same sensor is open instead, the display reads E4.
E8 at a glance
- Code
- E8
- Appliance
- U-Line ice machine
- Applies to
- U-Line UONB115 and UHNP315 ice makers
- Type
- Needs attention soon
- Can you clear it yourself?
- Sometimes, after the safe checks below
- Most likely cause
- Thermistor 4 has shorted internally
What you may notice with E8
- E8 stays on the display of the ice machine.
- The ice cycle seems slower than before.
- You might find water near the cabinet.
- Everything else, such as lights and the door, behaves normally.
How the ice machine detects E8
Thermistor 4 is the fourth temperature sensor the control relies on, and it reports in the same way as the others: its resistance changes with temperature and the control reads that change. The reading normally stays in a believable range. When a short occurs, the resistance collapses and the control sees something it cannot match to any real temperature.
It answers by showing E8 and treating the fourth reading as invalid. The ice cycle depends on that reading for part of its timing, so the cycle slows and less ice is made. The short can be inside the sensor, along a lead that has been damaged, or at a connector exposed to water. Looking at the machine will not settle which, so a meter test of the circuit comes first. The clear ice UCLR1215 never shows E8.
Likely causes of E8
- Thermistor 4 has shorted internally
- The fourth sensor's lead is damaged along its run
- Moisture has reached the fourth sensor's connector
Can you keep using the ice machine with E8?
The machine can run in the meantime, though it will produce less ice. E8 is a sensor signal problem and not a safety warning in itself. Switch the machine off and unplug it if you find water around the cabinet, and leave the panels alone. A repeat of E8 after a restart means the sensor circuit should be tested.
What you can safely check
- Switch the machine off for a minute so nothing is running.
- Switch it on again and watch the display.
- Look around the cabinet for water and wipe it up.
- Make sure the bin door is shut.
- Do not open panels.
- Contact us the moment E8 shows up again.
What our technician does for E8
- Test Thermistor 4 for a short with a meter
- Check the lead and plug for damage or moisture
- Check the board if the sensor tests good
- Replace what fails and confirm E8 does not return
How to keep E8 from coming back
- Keep the floor around the machine dry and clean up leaks quickly.
- Avoid hosing or splashing the cabinet near the sensor area.
- Check the clearance behind the machine so cables are not crushed against the wall.
Technical reference
- Code
- E8
- Appliance
- U-Line ice machine
- Control family
- U-Line UONB115 and UHNP315 ice makers
- 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
E8 questions
What does E8 say about the fourth sensor?
It says Thermistor 4 is shorted. The control receives a value that no real temperature could give, so the fourth reading is lost and the ice cycle runs poorly.
Is E8 related to E4?
Yes. E4 reports that same sensor as open, and E8 reports it as shorted. A technician reads the two together, since both lead back to the fourth sensor circuit.
Should I try anything before I ask for a repair?
Restarting the machine is a safe first step. If E8 returns, the cause is somewhere along the sensor path, so the circuit needs a proper test.
Does E8 mean the board has failed?
Not necessarily. A short can come from the sensor, the lead or the plug, and the board is only one of the places we test. We check the cheaper and likelier parts first, then the board if the rest pass.
Will E8 clear once the machine dries out?
It can, when the only problem was dampness at the connector. If the code remains after the area is dry and the machine is restarted, the short is real and the circuit needs testing.
Need help with E8?
A technician finds the cause at your bar or lanai and puts the price in writing before any part comes out.