Does the board show that it has gone off on a safety? Also is the machine air or remote? If you are at the job call factory, they can really help you.

 

Ya the damn factory always takes forever to call me back.

There is no safety that it shows in the code. I really suck with diagnosing ice machines, I get the job done, and done right but it just takes me some extra time.


One of the guys at work said just replace the probe thats what it will be. He said they get tempermental after a while. What is you guys input on that?

 

Check to see that the grid is not separating. Also check the cube thickens. If they cleaned it that way it may be time for a Hosi!

 

i have never seen a manitowoc ice up due to bad ice probe. guess it could happen but i would be looking for water inlet problem not allowing ice fill at top of plate. hanging up inlet or dump valve.

 

i had similar issue & as everyone knows not all problems are alike ... however i found the ice probe scaled slightly .. could barely notice by quick glance but after pushing probe up to sheet & not getting red light, i grounded probe lead at board for quick second, got my light .. grounded probe near ice sheet, but part not in contact with water ..light .....ok obviously its the probe so for i checked reading across probe & like a switch that b!tch should be 0.00 ohms ( from water end to board end )... that sucker was jumpin around in the 100's .. cleaned it very thouroughly with steel wool ( is that bad ? ) its worked fine since .. i could have changed it but that probe aint making my boss rich so .. oh well ..... only thing initiating harvest is that probe & board after probe fails to do so ... but hey that was my experience ....all u people love a HOSHI ... I wish i seen more of those .. only one of my accounts have a hoshi km1200 .. the rest manitowoc

 

Steve,

Turn the machine "OFF" then back "ON" and look for the number of times that the LED light on the board blinks. If memory serves me right, it will blink ONCE or TWICE, old machines(J series) could blink about four different codes. These machines will do an "Extended Freeze" or "Extended Harvest" This may help you. Is there an Aireco supply near you? They do Manitowoc around here and you can get one of there little orange books. Pull the sensor and clean real good with IM cleaner and DRY very good before replacing. Good luck. Where is R12or Icemeister when you really need them?

 

Wouldn't it be nice if Manitowocs' had a visual or an audible alarm for their critical errors?

Don't know what error code the machine may be showing.
May I suggest that you pay particular attention to the head pressure if it's a remote and suction harvest pressure.

The HPR valves are always a nuisance. I don't understand how they can engineer a CVD system but can not get away from an HPR.

 

After talking to the customer, I found that they adjusted the ice thickness probe AFTER it froze up, and the unit dumped ice according to the customer. But it still doesn't work anymore.

I'll go out there and check for the basic things, mainly for that little red light when the ice starts to get thicker. I will update you guys on what I find.

In the meantime I am going to search for that little yellow manitowoc book. Well i think its yellow

 

hvacsteve82......

The model number would help. (along with some more info)

From your OP, it appears as though you have the book on this machine, correct? You stated that on the first call, the customer had reported the machine being heavily iced up but it sounded like by the time you got there the evaporator was cleared of ice.......so you never have seen it in a frozen up condition.

Tell the customer not to mess with it and leave it on until you get there so you can have a chance to observe what's happening.

The probe may appear clean but they will fool you. A good cleaning/rinse/dry will usually solve a dirty probe problem.............a new one will for sure. Be sure to adjust for the proper bridge thickness.

Check the sensor grounds. Check the machine ground. They can cause intermittent problems like this.

How long is the harvest time? That usually tells me a lot
about the condition of the evaporator. It should be 1-1.5 minutes. 2 minutes or more not so good. If it's a remote, a bad HPR will slow the harvest way down too.

They weren't using oven cleaner on the evaporator were they?

 

They used the oven cleaner on the whole damn thing. We will see what happens today. I will keep you guys updated...and take some accurate freeze, harvest, times.

 

Oh, and it is model number QD452A.

 

The yellow book is for the S-Series machines and the orange one is for flakers. The Q book is called goldenrod I believe.

First check for safety limit codes.....eith one or two flashes. In my book it starts on page 77. One flash is excessive freeze times and two is excessive harvest times. There are two versions on control boards for the Q machines. The older one has a black microprocessor and the newer one has an orange label on the processor.

The old board would set a safety limit #1 after three consecutive 60 minute harvest times. The new one is increased to six times. The #2 safety limit used to be three consecutive 3.5 minute harvests and is now 500. Since you just changed out the board, you should have the newer orange label controller.

Why was the board changed out, anyway? What was found that made you do that? I've never changed a Q board yet.

Set up the thickness probe properly and run through a cycle or two, checking basic times.....particularly the harvest time.

If you're not within the specs per the book, run through the operation analysis using the chart in the book. It'll usually point out where the problem lies.

That oven cleaner could easily ruin a perfectly good evaporator you know. I suspect your customer is a big part of the problem here.

 

Another possible item is: Is it grounded properly?
You changed the board is there a wire loose? The newer S models are very picky and the Q's did have a few problems with grounding issues.

Follow icemeister advise also!


Yuma,

 

Manitowoc svc manuals

Just download the thing. Here's the link-

http://www.manitowocice.com/Service/ServiceManuals.asp

They have all the different models listed, click on "Q models".
You'll want to download the analysis chart as well.
http://www.manitowocice.com/Service/AnalysisCharts.asp Alot of guys don't have the patience or knowledge to follow the charts accuratly, but they work. These are what the factory guys are doing most of the time when you call them anyway.

 

Ok,I called the goldenrod book yellow. I also have the orage book. I carry 12 or 13 books in my work van. I have most of the manitowoc books. Sometimes I can get a little lazy diagnosing them because I am always pressed for time, and ice machines do take some time for me to diagnose and test.

Today I took my time. The machine was not going into harvest, well it was but the compressor stayed in freeze mode. After checking it out further and taking a close look at the hot gas valve and the 120 v connectors were not pushed on all the way!!!!! Anyway I pushed them on. Checked out the system and it was working fine. I adjusted the ice thickness, watched it drop perfectly 5 times. Harvest time was 1 minute 15 seconds give or take 3 or 4 seconds each time. There is 2 little cracks in the white plastic on the left side of the evaporator. I am afraid ice may get caught up in there when it goes to dump in the future. I did make a note of it tho on the invoice to cover my a$$.


The ground on the system was checked 100% when I was diagnosing the board. The reason why the board was changed out was when I would put a jumper between the ice thickness terminal on the board and on a GOOD ground in the ice machine, the harvest light would not come on. And yes this was after it was in ice for a few minutes. The system worked great after I replaced the board.

I am not sure how the terminals got loose. The customer was in there poking around and "cleaning" the ice machine. These damn Pizza Hut Managers will do anything to keep their spending down to get their $500 quarterly bonus or whatever they get.

I appreciate all your help guys!

 

ive seen some crazy sh!t as far as products used to clean ice machines .. normally only at chinese restaurants .... only time they want u in there is to fix a breakdown .. never for a cleaning only ...i heard once that a dude used toilet bowl cleaner, turned the evap black .. they have a real issue with spending money & those folks make alot of cash