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  1. #1
    Join Date
    Jul 2002
    Location
    SE Texas
    Posts
    442

    Hobart C64A Dishwasher Issue

    Can someone tell me what determines the water levels in the wash and rinse tanks? The only manual I have is the replacement parts manual. I'm showing two floats in the wash tank and one float in the rinse tank. In addition, I'm showing two probes in the wash tank and one probe in the rinse tank. One probe in the wash tank is a 2-wire probe & switch assembly (water level) and one is a 4-wire probe & switch assembly (temperature & water level). The one probe in the rinse tank is either a 2-wire or a 4-wire probe & switch assembly. The parts breakdown shows both. I'm fairly certain one or both floats are to prevent the heating elements from energizing if the water level is too low, but I'm not sure if they control the fill level in the tanks. I don't think they do. I'm thinking the probes do that.

    I've tried talking to Hobart technical support, but the guy I talked to wasn't very helpful and basically, he treated me like I was an idiot. He did, however, tell me that the rinse tank was a slave to the wash tank and hinted that I might have water pressure issues, but that's as far as he would go.

    Thanks in advance for any guidance you can offer.

  2. #2
    Join Date
    Dec 2010
    Location
    New Orleans
    Posts
    1,012
    Believe it or not I have the same exact problem with a hobart as well, the tech will be here soon but I checked the floats for continuity and they worked but the solenoid will not stop the water flow. It is telling me their is a high temp. probe prob. We'll see what the tech says.

  3. #3
    Join Date
    Jul 2002
    Location
    SE Texas
    Posts
    442
    FYI, I've come to the conclusion that the kitchen staff didn't completely drain the rinse tank when they left for the day. Since both the wash tank and the rinse tank are fed from the same source and one fill solenoid, they both should get the same amount of water at the same time. Granted, the water line feeding the rinse tank could be restricted, which would not allow as much water into the tank and visa versa, but there are no restrictions.

    When Hobart tech support told me "the rinse tank is a slave to the wash tank, I wasn't exactly sure what he meant by that. But, now that I've had time to think about it and the fact that the wash tank has the probe that senses water level, it all makes sense now.

    I started the machine with both tanks empty several times over a couple of days and both tanks are filling to the same level. I don't think there was ever an issue. BTW, I called Hobart back and asked if I could get copies of service and troubleshooting manuals and was told I could not get them from Hobart. I would need to check with my local Hobart distributor, which I have yet to do, but knowing Hobart, I don't think it's going to happen.

  4. #4
    Join Date
    Dec 2010
    Location
    New Orleans
    Posts
    1,012
    The tech. said it was a bad high temp. switch which is the one and same as the float switch so he is ordering a new one will see what happens.

  5. #5
    Join Date
    Sep 2007
    Posts
    67

    manual for hobart

    try this : http://kitchen.manualsonline.com/man...duct_list.html


    just google it .

    sorry you probably have finished this project but here is away to get manuals.

  6. #6
    Join Date
    Jul 2002
    Location
    SE Texas
    Posts
    442
    Quote Originally Posted by johnnyb View Post
    try this : http://kitchen.manualsonline.com/man...duct_list.html


    just google it .

    sorry you probably have finished this project but here is away to get manuals.
    Yeah, I have that. Not really a service/troubleshooting manual. More of an installation/operation manual. Thanks anyway.

  7. #7
    Join Date
    Sep 2011
    Location
    Maryland
    Posts
    38
    In a multi tank dishwasher the water runs from clean to dirty. The rinse will overfill from the final rinse spray and overflow into the wash tank. This tank in turn will overflow into the prewash tank if one is present and so forth to the drain on the dirty end of the machine. The tank level is determined by the overflow tube or drain pipe in each tank. Floats will control the elements. Filling is usually timed when the machine is turned on.

  8. #8
    Join Date
    Jul 2002
    Location
    SE Texas
    Posts
    442

    Update

    I thought I'd give everyone an update.

    It turns out there was another float in the wash tank that I hadn't noticed. This third float is the float that activates/deactivates the water fill solenoid. The other floats are much lower than the upper float, so that's why I was confused as to how the water level was determined.

    This float, does indeed, control the water level in both wash and rinse tanks, as Hobart technical support meant when he said the rinse tank was a slave to the wash tank. When the wash tank water level gets low enough to cause the float to activate the fill valve, the rinse tank gets water at the same time, even if it doesn't need water. The excess water goes down the overflow drain tube until the wash tank is full.

    Now, on to the latest development in my ongoing dishwasher saga - final rinse temperature. I can't keep a constant 180 degree F final rinse temperature. The booster heater, a Vanguard 165N, is not keeping up with the demand. During the first three or four trays, things are fine. Then, not only does the final rinse solenoid activate, the fill solenoid activates while the machine is running. With both the fill and final rinse solenoids open, this is what is causing my final rinse temperature to drop below 180 degrees F. The booster heater can't keep up with the demand. For some reason, I'm losing several inches of water from the wash tank while the machine is running. Oddly enough, I'm losing very little water from the rinse tank. During the wash cycle, I'm noticing an excessive amount of water coming out of the drain. When the last tray goes through and the machine shuts down, the fill solenoid is open and letting water into the tanks. When I open up the inspection doors, sure enough, the wash tank has lost at least 6" of water. I've checked the O-ring on the overflow tube and it looks okay. Plus, when the tanks are full and the machine is idle, there is no water coming out of the drain. The only things I can think are happening are the fill tube is not remaining seated properly during the wash cycle or some how water from the wash side is making its way into the rinse side. This is what I have to figure out.

    I'm going to pull the overflow tube and put something over the wash tank drain to keep water from going down the drain and see if I lose water during the wash cycle. That should tell me for sure if I've got a problem with the overflow tube not seating properly when the machine is running. If doing this doesn't solve the issue, I've definitely got an issue with water from the wash side making its way into the rinse side. How that would be happening, I haven't figured out just yet. But, I will.

    By the way, I finally got a copy of the elusive Hobart service manual. I kept hounding Hobart until they sent me one.

  9. #9
    Join Date
    Jul 2002
    Location
    SE Texas
    Posts
    442

    Conclusion

    I couldn't help myself. The school is only a couple of miles from my house. I had to go in today to get this figured out. It was driving me crazy!

    Keep in mind, I just started working for the school district in September. Prior to that, though I had some kitchen experience, I had never worked on a dishwasher in my life!

    I found the problem. Water was making its way from the wash tank to the rinse tank because someone had put two curtains on the same hooks. If you look at the attached image, you'll see there is supposed to be two long curtains between the wash and rinse tanks. Someone had taken the curtain on the left and hung it with the curtain on the right. Someone who has no experience working on this particular dishwasher, like me, would never have noticed the curtain was missing and you really couldn't tell there were two curtains on the same hooks. I started the dishwasher and ran 20 trays back-to-back-to-back and my rinse water temperature stayed above 180 degrees F the whole time. Not once did the fill valve open and the wash tank still had plenty of water in it.

    I am so relieved to get this issue off my back! Hopefully, I score some brownie points with my boss, too.
    Attached Images Attached Images  

  10. #10
    Join Date
    Jul 2012
    Location
    las vegas, nevada
    Posts
    12
    if this can help........what determines your water level is your floats you've got one at the bottom on up top that tells the pc board when to open the fill solenoid..one prove goes to your temps.....is this steam or electric heater? you can bypass your probes to test them........

  11. #11

    uugggg hobart.....

    I feel your pain with hobart.....while they are good equipment they can be a pain and hobart is never much help. I have a c44 thats been giving me a fit........glad you got your problem figured out. I have 5 school kitchens myself that I maintain and I know all to well how it goes. I also have an old hobart put in back in the mid 60s and its on its last leg and parts are becoming harder to get. Good luck with your equipment and hope you can keep those brownie points going lol...............

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