Manitowoc Ice Machine Error Code E24: T4 Temperature Sensor
E24 means the T4 thermistor, which reads the evaporator outlet, is out of its valid range on a Manitowoc Indigo ice machine. Note whether slabs look normal and the machine cycles as usual, keep the evaporator area clear, and do not pull on sensor wires. Tell us E24 appears in the log.
Low: the machine keeps making ice while one sensor input is lost.
- Code
- E24
- Maker
- Manitowoc
- Equipment
- Ice machines
- Applies to
- Indigo series (non-NXT) control board, Event Log (Service menu > Event Log > View ELog)
What does Manitowoc error code E24 mean?
E24 is logged on Manitowoc Indigo ice machines without the NXT display when the T4 thermistor, which reads the evaporator outlet, goes outside its valid range. The control board needs T4 to judge superheat and to test whether the evaporator is starved or flooded. Superheat is the temperature rise of the refrigerant leaving the evaporator, and it shows whether the evaporator is getting the right amount of refrigerant. Without a good reading those protections weaken, and ice quality can drift. Ice may look normal in the meantime. The display text for the entry is E24. As with the other sensor entries, the reasons are physical: a loose connector at the evaporator outlet, a damaged wire or insulation on the outlet sensor, a sensor that has lost contact with the outlet line, or a thermistor that has failed open or shorted. A technician measures the sensor before acting.
Affected models and control systems
Manitowoc Indigo series cubers with the non-NXT control board (Service menu > Event Log > View ELog). E24 concerns T4 at the evaporator outlet; T3 at the inlet logs E23.
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
- Usually normal-looking ice
- Slabs that drift thicker or thinner over days
- Occasional odd freeze times
- The E24 line in the Event Log
Possible causes
Listed in Manitowoc's documentation
- A loose T4 thermistor connector at the evaporator outlet
- Damaged wire or insulation on the T4 outlet sensor
- A T4 sensor that has lost contact with the outlet line
- A shorted or open T4 thermistor
Other likely causes — what usually sits behind error code E24 on this control. A technician confirms which one it is before any part is replaced.
- A sensor wire chafed against the suction line where it leaves the evaporator
- A loosened sensor clip that lets the outlet reading follow room air
- Condensation dripping into the connector in humid weather
Safe checks before calling for service
- Note whether ice slabs look normal and the machine cycles as usual.
- Keep the area around the evaporator clear.
- Do not pull on sensor wires.
- Call us and tell us E24 appears in the log.
How a technician diagnoses error code E24
- Read the Event Log for E24 and look at E23, E07 and E08 entries.
- Inspect the T4 connector and wire where they leave the evaporator.
- Check sensor contact and insulation on the outlet line.
- Measure thermistor resistance against the chart.
- Replace the sensor only after the meter test.
- T4 feeds the superheat judgment, so a wrong reading can cause a wrong repair if it is not tested first.
- The outlet line sits close to cold surfaces and moisture, which raises the risk when handling wiring.
- Measuring resistance with the right chart is a technician task.
How error code E24 differs from similar codes
E24 is the outlet reading that, with E23's inlet reading, lets the board decide on starving or flooding.
Technical reference
- Document
- Indigo Series Technician's Handbook 000014794 5/17, "Event Log" p.87-91
- Maker documentation
- Manitowoc owner support
- Edition
- Part Number 000014794 5/17
- Models / control
- Indigo series (non-NXT) control board, Event Log (Service menu > Event Log > View ELog)
- Section
- Event Log: code list p. 87, Event Log Detail table pp. 88-91 (Service menu > Event Log)
- 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 Manitowoc ice machine error codes
Can I keep running the machine with E24?
Yes, usually, but the superheat check is weaker, so ice quality can drift.
Will E24 clear by itself?
Only if a loose connection settles. A damaged sensor or wire stays out of range.
Is E24 the same as E07?
No. E07 is a refrigerant feed problem. E24 is a bad sensor reading that can make those checks unreliable.
Need help with Manitowoc error code E24?
A technician confirms the cause on site and gives you the price in writing before any work starts.