--- title: "Manitowoc SL1 light: safety limit 1, freeze time too long" description: "What SL1 means on Manitowoc SL1 light: safety limit 1, freeze time too longs, what to check before booking, and when it is not a failure at all." url: "https://icemachinerepair.center/error-codes/manitowoc-sl1/" --- # Manitowoc SL1 light: safety limit 1, freeze time too long Before the Event Log, Manitowoc boards reported the same long-freeze problem with lights. ## What SL1 actually means. Before the Event Log, Manitowoc boards reported the same long-freeze problem with lights. On Indigo boards a control board light labeled SL1 flashes. On Q210 and Q270 undercounters there is no SL light; the harvest light flashes continuously, and after the toggle switch is cycled it flashes once for safety limit 1. The Q-series waits an hour in standby after the first stop and stays off after the second. Manitowoc ice machine display What to do when SL1 shows on the ice machine ### Kind of code Harvest and freeze cycle A freeze ran longer than the board allows, or a harvest started and the ice never fell. Scale on the evaporator holds the sheet to the plate, a thickness probe crusted with minerals never signals, a hot gas valve that does not open leaves the plate cold, a harvest assist that does not push, or a water curtain that swings without tripping its switch all end in this family. A cleaning cycle run by the manual often clears it; a valve or a probe is a technician's job. ### Usually leads to Ice machine harvest repair The hot gas valve, harvest assist, curtain switch and thickness probe that decide when a sheet of cubes is done and make it drop. ### Shows up as Ice Machine Error Code or Flashing Light: What It Is Telling You An ice machine error code may show as a number on a small display, a pattern of blinking lights on the control board, a colored light on the front, or a machine that stops with one indicator flashing. ### Make Manitowoc With a Manitowoc ice machine, the technician notes what the controls report and checks the bin control before opening the cycle for testing. ### Source Manitowoc Indigo ice machines installation, operation and maintenance manual (Part Number 000013325 Rev 02) Indigo control boards (SL1 light) and Q210/Q270 undercounters (harvest light flashing once). The same event appears as E01 in Indigo Event Logs. ## Before you book, in this order. Each step comes from Manitowoc's own guidance for SL1 on its ice machines. Follow it to the end: the last card says whether this is a visit. 01 Move the toggle or On/Off switch to Off and back on, then count the flashes to confirm it is limit 1. 02 Check that the water is on and the condenser has room to breathe. 03 Let the head restart; if it stops on the same limit again, book a visit. ### Still there? It usually turns into [ice machine harvest repair](https://icemachinerepair.center/services/ice-machine-harvest-repair/). Book with the code and the model number. ### What not to do SL1 does not mean the machine has no power; the light proves the board is alive. Two flashes point to safety limit 2, the long harvest, instead. ## What you may notice with it. The ice machine problems SL1 tends to arrive with. Answer these at the ice machine before anyone is booked. [All problems](https://icemachinerepair.center/problems/) Before you call ### [Ice Machine Error Code or Flashing Light: What It Is Telling You](https://icemachinerepair.center/problems/ice-machine-error-code/) [All 7 causes, cheapest first](https://icemachinerepair.center/problems/ice-machine-error-code/) It also comes with - [**Ice Machine Running but Not Making Ice**](https://icemachinerepair.center/problems/ice-machine-not-making-ice/) - [**Ice Machine Making Too Little Ice for the Rush**](https://icemachinerepair.center/problems/ice-machine-making-little-ice/) Problem ### Ice Machine Error Code or Flashing Light: What It Is Telling You 7 causes, cheapest first Where SL1 usually leads ## Ice machine harvest repair. **Thickness probe, curtain switch, harvest assist and hot gas valve · low to moderate.** Book a visit [What the job involves](https://icemachinerepair.center/services/ice-machine-harvest-repair/) ## Manitowoc ice machines. With a Manitowoc ice machine, the technician notes what the controls report and checks the bin control before opening the cycle for testing. [Manitowoc ice machine repair](https://icemachinerepair.center/brands/manitowoc/) More Manitowoc codes [E01](https://icemachinerepair.center/error-codes/manitowoc-e01/) [E02](https://icemachinerepair.center/error-codes/manitowoc-e02/) [E03](https://icemachinerepair.center/error-codes/manitowoc-e03/) [E04](https://icemachinerepair.center/error-codes/manitowoc-e04/) [E05](https://icemachinerepair.center/error-codes/manitowoc-e05/) [E11](https://icemachinerepair.center/error-codes/manitowoc-e11/) [E12](https://icemachinerepair.center/error-codes/manitowoc-e12/) [E19](https://icemachinerepair.center/error-codes/manitowoc-e19/) [E20](https://icemachinerepair.center/error-codes/manitowoc-e20/) [E21](https://icemachinerepair.center/error-codes/manitowoc-e21/) [E25](https://icemachinerepair.center/error-codes/manitowoc-e25/) [E28](https://icemachinerepair.center/error-codes/manitowoc-e28/) [All 15 Manitowoc codes](https://icemachinerepair.center/error-codes/#codes-manitowoc) Harvest and freeze cycle on other makes [Atosa E2](https://icemachinerepair.center/error-codes/atosa-e2/) [Blue Air E1](https://icemachinerepair.center/error-codes/blue-air-e1/) [Follett HI AMPS](https://icemachinerepair.center/error-codes/follett-hi-amps/) [Hoshizaki 1 beep](https://icemachinerepair.center/error-codes/hoshizaki-1-beep/) [Ice-O-Matic Error 1](https://icemachinerepair.center/error-codes/ice-o-matic-error-1/) [Koolaire SL#1](https://icemachinerepair.center/error-codes/koolaire-sl1/) [Scotsman 1](https://icemachinerepair.center/error-codes/scotsman-1/) [Sub-Zero ICE flashing](https://icemachinerepair.center/error-codes/sub-zero-ice-flashing/) [All 23 codes of this kind](https://icemachinerepair.center/error-codes/#family-harvest) Manitowoc builds this ### Modular ice machine An ice-making head set on top of a separate storage bin or drink dispenser, cooled by air, water or a condenser on the roof, turning out hundreds of pounds of cubes a day. Manitowoc builds this ### Undercounter ice machine A self-contained ice machine that makes and stores its own ice under a bar, a service counter or a kitchen island, from commercial units to clear-ice models in large homes. Manitowoc builds this ### Nugget ice machine An ice machine that freezes a thin layer inside a chilled cylinder and pushes it out with an auger as soft, chewable nuggets, for clinics, offices, hotels and large homes. ## In Manitowoc's own words > A safety limit is indicated by a flashing control board light labeled SL1 or SL2. [Manitowoc Indigo ice machines installation, operation and maintenance manual (Part Number 000013325 Rev 02)](https://www.manitowocice.com/asset/?id=bbkvh) [Manitowoc Q210/Q270 undercounter ice machines technician's handbook (Part Number STH039)](https://www.manitowocice.com/asset/?id=bqhvu) [Manitowoc Q210/Q270 undercounter ice machines technician's handbook (Part Number STH039)](https://www.manitowocice.com/asset/?id=bqhvu) Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. Indigo control boards (SL1 light) and Q210/Q270 undercounters (harvest light flashing once). The same event appears as E01 in Indigo Event Logs. ## Manitowoc SL1 ice machine repair, where we come out. The same visit in every metro below: the code, the model number, and a diagnosis before any part is ordered. 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Move the toggle or On/Off switch to Off and back on, then count the flashes to confirm it is limit 1. If it comes back, it needs a visit. ### Where is the SL1 light on my Manitowoc? It is on the control board inside the head, not on the front panel, so it is usually a technician who sees it. The front display on Indigo heads shows an alert instead. ### My Manitowoc undercounter waited an hour and restarted. Is that SL1? On Q210 and Q270 units, yes: the first safety limit stop is a 60-minute standby. If the same limit is reached again, it stays off until restarted by hand. ### Is SL1 the same as E01 on a Manitowoc? They describe the same long-freeze event. SL1 is the board light; E01 is the Event Log entry on Indigo heads that have a log. --- **[Read on the site: Manitowoc SL1 light: safety limit 1, freeze time too long](https://icemachinerepair.center/error-codes/manitowoc-sl1/)** **[Book a visit with IceMachineRepair.center](https://icemachinerepair.center/schedule/)**