Safety Limit #2 On Manitowoc Ice Machine January 09 2014, 133 Comments
When your Manitowoc ice machine shuts down prematurely, it most likely is going off on what’s called a safety limit. On Q Series ice machines there are 2 different safety limits, that will help you diagnose the problem. To check the which safety limit is the problem, simply turn your machine from the off position to ice and count how many times the harvest light flashes. Below are what the 2 safety limits mean.
Safety Limit #1 : If the freeze time reaches 60 minutes, the control board automatically initiates a harvest cycle. If 3 consecutive 60-minute freeze cycles occur, the ice machine stops.
Safety Limit #2 : If the harvest time reaches 3.5 minutes, the control board automatically returns the ice machine to the freeze cycle. If three consecutive 3.5 minute harvest cycles occur, the ice machine stops.
Safety Limit #2 is a more common safety limit and can be caused by the ice maker simply being dirty. A dirty evaporator will hold ice and not allow it to fall until it is mostly melted away. Because there is not enough ice to force the water curtain open and break the bin switch, the machine simply thinks it never harvested.
Assuming your ice machine is clean, there are 2 other areas that are most common for shutting a Manitowoc Ice machine down on a safety limit #2. A missing magnet on the water curtain or your water curtain being broken will cause your bin switch to fail. The magnetic bin switch on a Manitowoc ice machine relies on proximity to the magnet to know when to terminate the harvest cycle. This switch will not read if it does not make proper contact with the magnet. To remedy this issue simply replace the water curtain.
Another culprit, which can also lead to intermittent problems, is a failed bin switch. The only way to properly test a magnetic bin switch is to OHM it out and look for consistency. However, it is possible for the switch to fail on say the 100th time, so if you are experiencing regular Safety Limit #2 lockouts, it might be a good idea to go ahead and eliminate the bin switch by replacing it.
Lastly, never underestimate a good cleaning. Most Manitowoc ice machine problems can be fixed without any parts, simply a good cleaning will return the ice maker back to proper operation. If you have any questions about diagnosing or replacing Manitowoc ice machine parts, ask your question below in the comment section.
Comments
I have a Manitowoc QD0212a.
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Lynn - Ice Maker Parts Shop Admin on June 06 2014 at 02:28PM
@everett, this is typically caused by an ice thickness control, as this is the only component to put the ice machine into defrost or harvest cycle. I would recommend disconnecting the ice thickness control directly from the board, turning the machine on, and watching the cycle. If it freezes, then replace the ice thickness control. If it still goes into harvest, you may have a failing control board.
Let me know the model number of your ice machine and I’ll gladly assist with parts research and tell you the part number to order.
everett on June 04 2014 at 06:32PM
I working on a manitowoc q when I turn it on it goes into a freeze cycle, but in bout 1 minute it changes to defrost cycle and shuts down. Not enough time to trouble shoot the problem. It blinks a safety2 but want run long enough to check any thing. Whats the deal?
Lynn - Ice Maker Parts Shop Admin on May 22 2014 at 08:58PM
@mike the probe you need is a single wire probe replacement, if you have the double wire original. The part number is 7627813 and can be found at the link below:
http://icemakerpartsshop.com/products/76-2781-3-manitowoc-ice-thickness-control
mike meagher on May 22 2014 at 04:54PM
I am having trouble with my manitowoc mode# 0254A series 250 ice machine. Can you help.
mike meagher on May 22 2014 at 04:23PM
My Manitowoc 250 series ice machine mode # JY0254A is not making ice. I was reading some of your e-mails and fond 1 closed to my problem. so I disconnected the ice thickness probe. I got a good sheet of ice. So it wright now it looks like the problem. Is there a nother way to test? And where can I get the probe? And what does it cost?
Lynn - Ice Maker Parts Shop Admin on May 19 2014 at 08:41AM
@Michael unfortunately the B570 is the storage bin and not the ice machine model number. Do you have the top piece of equipment model?
HPCO means that the condenser is likely clogged or the fan motor is not running. These would be the first things I would check, no matter the model number of ice machine you have.
MICHAEL on May 18 2014 at 12:03AM
MODEL B570. POWER WENT OUT THREE TIMES OVER A FEW HOURS . MACHINE WILL NOT STAY RUNNING.
IF YOU TURN POWER OFF AND ON IT TELLS YOU DELAY XX MINUTES (COUNTS DOWN) AND BELOW THATS SAYS HPCO ACTIVE. HELP!!!!
Lynn - Ice Maker Parts Shop Admin on May 15 2014 at 08:55AM
@Wayne if by tapping on the control box it starts working again, it could be a stuck relay. It would be unlikely, but I suppose a possibility. I’m guessing it might have to do with a lose connection to your inlet valve, water supply, or something of the like.
First thing I would do is remove your valves, make sure they are clean and free of debris. Was this machine properly winterized before storage?
Wayne on May 13 2014 at 02:19PM
I have a Manitowoc BD0152A. It was working fine last summer before I stored it away for the winter. Now that I want to use it again, it is having problems. It runs good, ice cells get cold but water only flows intermittently. When water stops flowing, I tap the electrical panel with my palm and it starts flowing again. But only for a minute or so. Could there be a short on the board? Where would I start looking?
Lynn - Admin of Ice Maker Parts Shop on May 11 2014 at 06:03PM
@Kofi, it’s possible your machine is going into harvest immediately. I would need to know when the harvest cycle is initiated. The safety limit #2 would indicate that your ice thickness probe may be reading incorrectly. This is the first place I would start.
Unplug the probe directly from the board, turn the machine on, and see if it makes ice. With the ice thickness control unplugged, it should just make a big sheet of ice until you turn the machine off. If it does make a sheet of ice, we’ve isolated the problem, your ice thickness control needs replaced.
Kofi on May 10 2014 at 06:46AM
Hello,
I have a manitowoc jy1305w ice machine. The ice machine starts up and runs but never forms ice. It runs for about 20-30 mins and turns off by itself. All indications are that it’s a safety limit 2 code because after turning the machine off and back to the ice position, the light flashes twice. Anyways, the machine has never formed ice during this process. I have changed the bin switch, cleaned the machine and currently doing the 100th time thing to reset the safety limit code. Any ideas pls on what to do to ensure the machine makes ice
Lynn on May 08 2014 at 08:49AM
Erek, what is the temperature around the ice machine? Production can be significantly diminished by higher temperatures, even hitting 90 degrees in a kitchen can lower it’s production by 50-100 lbs.
Also, if this is a new installation, make sure they have it hooked up to the cold water line. Verify that the water temp is around 70 degrees as well. It’s been warming up, so if your water line runs over head or is shallow in the ground, it’s temperature could be high as well. Any heat will greatly lower ice production.
Erek on May 07 2014 at 04:52PM
it is a 220lb per 24 hr production machine.
with 80lb capacity bin.
But i have had it on for 24 hours now and it only has filled up not even halfway.
I cleaned the fins on the condenser located on the front left of machine, and even left the air filter off to get better air to it when I installed this 24 hours ago.
Not sure what it could be.
Lynn on April 15 2014 at 09:50AM
@Brian, you could verify that you have the write water inlet valve, which is a part number 000009123. I’m not aware of an intermittent valve problem, they usually either work or they don’t.
The best way to check would be to see if you are getting power to the valve when it’s letting water through. It’s possible there is a relay sticking on the control board, intermittently sending constant voltage, even when the machine is turned off. If you truly unplugged the ice machine and not just turned it off, then let me know and we can get a valve replaced under warranty for you.
You can contact me at sales@icemakerpartsshop.com
Brian on April 14 2014 at 07:27PM
I have a QY0454A. The water inlet valve was leaking as well as letting water flow in at all times, even with the machine unplugged. Ordered a new valve, installed, worked ok for about 30 minutes and then the exact same problem started happening. Pulled valve off and apart to check for debris, nothing found. Attempted to blow through the valve with my mouth and no air would pass. Hooked up to the machine turned on to check for proper operation of coil. Once the machine called for water the valve would open and I could blow through it. Shut the machine off and the valve closed. Put back on, checked water pressure to machine with gauge, 25psi. As soon as I turned the water on even with the machine unplugged water started to flow constantly. Could the new valve be bad or could the wrong valve have been sent? The hose connections from the old valve to the new were slightly different sizes and I had to adapt them.
Lynn on April 08 2014 at 08:05AM
@Jim, that machine uses a water level probe(2006549) and a water inlet valve(000009120). There are just a few things that could cause this problem. Either the water level probe is not sensing properly, the water inlet valve is stuck open, or the board has a relay stuck.
To check, look and see if the water level probe light comes on the board when water touches the water level probe. If it comes on, but continues to fill, then the water inlet valve is most likely stuck open. Sometimes trash can get stuck in it, holding it open, or the rubber gasket has failed inside.
However, if you are getting constant voltage to your inlet valve, no matter what the sensor says, then you have a stuck relay on a board. This is uncommon, but can happen. Most likely you have a bad water inlet valve that needs replaced.
Inlet valve for S300 – http://icemakerpartsshop.com/products/000009120-manitowoc-and-kool-aire-water-inlet-valve-115v
Jim Champion on April 07 2014 at 03:25PM
Model # SD0302A
Lynn on April 07 2014 at 09:31AM
@Jim, that would be caused by a stuck open water inlet valve or float valve. The water pump should only be used for pumping the water to the distribution tube and not actually bringing the water in.
Do you have the model number of your ice machine?
Jim Champion on April 07 2014 at 05:53AM
My ice machine will not quit pumping water. It’s making ice but the water is running over the fresh water tray and in to the ice bin melting the ice.
Lynn on March 31 2014 at 08:26AM
@S.R.Smith, sounds like your machine may be shutting off on some sort of safety limit. Also, I believe those had a thermistor on them, which could cause the machine to fail as you describe. I would recommend looking at your thermistor or jumping it out to see if it would run.
S.R. Smith on March 30 2014 at 10:13PM
My b series manitowoc ice machine stopped working after heavy use of a wedding. I have 24.6 volts into the board, can start the compressor by manually closing the contactor points. But there is no voltage at the rocker switch, no lights . The bin switch ohms out ok, any guesses on this one.
Lynn on March 12 2014 at 03:10PM
Charles, I would recommend disconnecting the ice thickness probe(unplug the terminal from the board) from the machine and turning it on. If the machine freezes a batch of ice without problem, but does not harvest. We know that the ice thickness control was bad. We are basically just removing it from the equation and the machine should operate as normal, just not go into harvest, as that’s all the ice thickness probe does.
Did you get the IT probe from Ice Maker Parts Shop? If you did, please contact me at sales@icemakerpartsshop.com and if it’s been recently we’ll for sure get you a replacement. Assuming this is the cause of the problem. If the machine still has the problems you described, with the IT probe disconnected, it could potentially be a bad board or grounding issue with the machine.
Charles Revill on March 12 2014 at 08:40AM
I replaced ice thickness probe and the bin switch when I start the machine the green ice light comes on for a couple of seconds and then the red harvest switch flashes and stays on then the machine goes back and forth from freeze to harvest you can here the compressor and the ice plate goes cold to hot I have not replace the curtain because the magnet seems ok and the curtain isn’t broke the model is jy0454a what could be the problem.
Lynn on March 08 2014 at 09:30AM
@Charles, all I need to know is the model number of your ice machine and I’ll gladly quote you a magnet replacement. However, please note, not all magnets can be replaced, it depends on the type of water curtain your ice machine uses.
Charles Melton on March 08 2014 at 06:18AM
Wherecan I find a magnet for my ice maker
Lynn on February 18 2014 at 01:05PM
Jerm, first thing would be to see why the trough is over flowing. Is the water level light on, when water makes contact with the probe? If it isn’t, then we need to fix that first.
Also, if you are constantly getting warm water into the trough, it might not make a batch of ice or kick off within it’s safety. Let me know what you find.
jerm on February 18 2014 at 12:09PM
Manitowoc sy0304a the safety limit 1 is blinking constantly and water starts over flowing out of the trough…the compressor is kicking on but the coils do not feel cold…the evaporator is clean
What might be the problem?
Lynn - Ice Maker Parts Shop Admin on January 21 2014 at 09:15AM
@Joe
Is it intermittent? An intermittent problem, as you describe, is mostly caused by a failing bin switch. This makes the machine think that it’s full and shut down, when it’s really not. The only way to test the switch is to OHM it out and look for consistency, over 100 open/closes.
How long does it stay in harvest?
Joe on January 20 2014 at 07:31PM
I have a q450 and it will cycle ones make one batch of ice then never make a second batch. Sounds as if he compressor is kicking out. Can you help?? I’ve had two service techs look at issue and no fix yet.
Lynn - Ice Maker Parts Shop Admin on January 20 2014 at 08:44AM
Josh, most modern ice machines, especially modulars do not have float valves. Manitowoc ice machines, 300lbs and larger come equipped with inlet valves and troughs that are not adjustable.
Josh on January 20 2014 at 02:01AM
Bend the hinge that holds the float so its deeper your water level is getting too high or adjust the trough
Lynn on January 19 2014 at 10:47AM
Phil, this would be caused by a leaking water inlet valve. When the power is off to the machine, the valve should be closed, if it’s leaking through then the internal plunger has probably been worn out.
We keep the replacement valve in stock, part number 000007966. Follow the link below to purchase.
http://icemakerpartsshop.com/collections/electrical-ice-maker-parts/products/000007966-manitowoc-208-230v-water-inlet-valve
Please let me know if there is anything else I can assist with.
Phil Mack on January 18 2014 at 09:18PM
Manitowoc QD0802A makes ice, harvests perfectly. I shut my ice machine off as I only need ice once per week. When machine is off, the water bin overflows, very slightly. Just drip, drip, drip. Probably loose a quart of water daily. What would be the cause of this? How can I correct this?