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  1. #1
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    Hobart LXEH UnderCounter Dish

    Anybody familiar with this dish machine?

    Machine displays drain on start up, drain pump does not run for 1 minute, then drain pump runs(no water to come out), then it shows warming up, then it shows FILL, but no water is coming in, then after 300 seconds it shows "sump level low Error, call for service".

    1. Customer says it never showed drain on startup before, it only showed fill on start up. But standard operation on most undercounters is that it initially drains, then it fills, so this is the first confusion.

    2. Second thing I found was a scale filter clogged with scale. Initially I thought this would solve it. cleaned up everything, installed new filter, checked that water is coming upto the fill valve solenoid. Water pressure on plumbing line shows 80 psi before the filter.

    3. When it displayed fill, board is not displaying red light near fill relay, i stuck my leads onto the fill valve pins and I am getting no voltage. This is a 120v fill valve. I removed the two wires, stuck my leads in the wires and I am reading 120v. Why no voltage when it is connected?

    4. I jump the fill test pins on the board, and it shows a red light and it fills the unit. so the fill solenoid valve is good.

    5. I see a black pressure transducer with a hose going down to the booster tank. i dont see a way of testing this device.

    So unless i jump these pins, there is no water entering the unit, I would conclude its the board and/or the pressure transducer, but I need to confirm.

    There is no wiring diagram to be found, no sequence of operation, customer called Hobart 3 times and two times they replaced the master board, but still not filling.

    Any help will be appreciated, a manual, schematic, sequence, anything pls.

    thanks Guys

  2. #2
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    It sounds like you are getting a ghost voltage reading meaning under load the voltage is not present. I would look to see if this is happening because of the neutral or the hot leg.

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  4. #3
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    What he said. ^^^

    Ghost voltage with no amps is often a sign of a failed relay. In your case, likely a board problem.

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  6. #4
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    Hos 4:6 My people are destroyed for lack of knowledge. Because you have rejected knowledge, I will also reject you, that you may be no priest to me. Because you have forgotten your God’s law, I will also forget your children.


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  7. #5
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    Quote Originally Posted by Rockwell View Post
    Anybody familiar with this dish machine?

    Machine displays drain on start up, drain pump does not run for 1 minute, then drain pump runs(no water to come out), then it shows warming up, then it shows FILL, but no water is coming in, then after 300 seconds it shows "sump level low Error, call for service".

    1. Customer says it never showed drain on startup before, it only showed fill on start up. But standard operation on most undercounters is that it initially drains, then it fills, so this is the first confusion.

    2. Second thing I found was a scale filter clogged with scale. Initially I thought this would solve it. cleaned up everything, installed new filter, checked that water is coming upto the fill valve solenoid. Water pressure on plumbing line shows 80 psi before the filter.

    3. When it displayed fill, board is not displaying red light near fill relay, i stuck my leads onto the fill valve pins and I am getting no voltage. This is a 120v fill valve. I removed the two wires, stuck my leads in the wires and I am reading 120v. Why no voltage when it is connected?

    4. I jump the fill test pins on the board, and it shows a red light and it fills the unit. so the fill solenoid valve is good.

    5. I see a black pressure transducer with a hose going down to the booster tank. i dont see a way of testing this device.

    So unless i jump these pins, there is no water entering the unit, I would conclude its the board and/or the pressure transducer, but I need to confirm.

    There is no wiring diagram to be found, no sequence of operation, customer called Hobart 3 times and two times they replaced the master board, but still not filling.

    Any help will be appreciated, a manual, schematic, sequence, anything pls.

    thanks Guys
    When u power on those units , it will go into a drain cycle ......once that's done it will d0 a first part fill up to the first water level probe in back right corner ......now the unit will sit and flash fill until the booster reaches temp before advancing to next fill stage.....also if your getting a sump probe error that's going to throw off the sequence.....this probe is at the front , try cleaning it first then replacing it....do this first and get back to me

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  9. #6
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    Quote Originally Posted by HVAC_Marc View Post
    What he said. ^^^

    Ghost voltage with no amps is often a sign of a failed relay. In your case, likely a board problem.
    Thanks EJBreeze.

    Marc, the manager says they have changed the board twice. What could be killing the board? Could it have something to do with very high water pressure? Its coming in at 80 psi with no regulator.

  10. #7
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    Quote Originally Posted by Dakota11 View Post
    When u power on those units , it will go into a drain cycle ......once that's done it will d0 a first part fill up to the first water level probe in back right corner ......now the unit will sit and flash fill until the booster reaches temp before advancing to next fill stage.....also if your getting a sump probe error that's going to throw off the sequence.....this probe is at the front , try cleaning it first then replacing it....do this first and get back to me
    Dakota, I do not see any probes on the back of this unit. I believe you are referring to the LXIH, which has a dual probe in the right rear. and a sump probe in the left front.

    I actually didnt see any probes in this unit's wash tank. It appears to be checking water level by a pressure switch.

  11. #8
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    Thread Starter
    Thank you, that was a bit helpful.

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  13. #9
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    Quote Originally Posted by Rockwell View Post
    Thanks EJBreeze.

    Marc, the manager says they have changed the board twice. What could be killing the board? Could it have something to do with very high water pressure? Its coming in at 80 psi with no regulator.
    Power surges, low voltage, moisture, someone unqualified F-ing with it.

    I wouldnt think it has to do with the water pressure. Though, I would reference the OEM manual to find out what it's supposed to be. The only thing I can think of is that the water pressure is holding the plunger in the closed position. But that shouldnt cause a relay burnout.

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  15. #10
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    Quote Originally Posted by Rockwell View Post
    Dakota, I do not see any probes on the back of this unit. I believe you are referring to the LXIH, which has a dual probe in the right rear. and a sump probe in the left front.

    I actually didnt see any probes in this unit's wash tank. It appears to be checking water level by a pressure switch.
    My apologies ......I didn't read it correctly , yes I was referring to the LXI ....sorry

  16. #11
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    On those units ive had to replace those water level sensors many times as the unit either thought it was full or not full......on your board D76 should be lit up red for fill solenoid ......
    Have you gone into the menu .....to the view stats section ? you can monitor in real time whats going on.....your sump water level reading should be approx. 450mv to 950 mv and your booster water level 450mv to 2000 mv

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  18. #12
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    Quote Originally Posted by Dakota11 View Post
    On those units ive had to replace those water level sensors many times as the unit either thought it was full or not full......on your board D76 should be lit up red for fill solenoid ......
    Have you gone into the menu .....to the view stats section ? you can monitor in real time whats going on.....your sump water level reading should be approx. 450mv to 950 mv and your booster water level 450mv to 2000 mv
    Yes, precisely. I got those numbers to be very accurate only when I manually fill the machine. So that led me to think whatever probes are in the sump and the booster is working properly. Its something in the fill circuit. Why would it only fill when I jump the pins but automatically it will not fill. Thats why I said its the board and they looked at me like I am crazy because it has been changed two times already.

    This thing also has a pressure switch. Could it be the pressure switch. But the pressure switch controls water level. Could it prevent filling when the board calls for filling? Because it completes the entire time cycle for fill even though no water is entering.

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  20. #13
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    Quote Originally Posted by Rockwell View Post
    Yes, precisely. I got those numbers to be very accurate only when I manually fill the machine. So that led me to think whatever probes are in the sump and the booster is working properly. Its something in the fill circuit. Why would it only fill when I jump the pins but automatically it will not fill. Thats why I said its the board and they looked at me like I am crazy because it has been changed two times already.

    This thing also has a pressure switch. Could it be the pressure switch. But the pressure switch controls water level. Could it prevent filling when the board calls for filling? Because it completes the entire time cycle for fill even though no water is entering.
    the water level sensors that I was referring to is the pressure switches that are located at the top back left and right corners . they have clear tubes running down to the air traps. I would replace them and check that those tubes have no holes in them .
    You said your getting water in unit when u shorted pins , so that confirms no obstructions in hose , solenoid working . It sounds like the unit thinks there is water when actually theres not .
    Check on the board that D1 is green and D2 is green( sump and booster water level )
    Also on the board there is a test points .....go to test point 35 to board ground , and test point 36 to board ground both should read when energize between .450 to 3.3 volts DC....this is your sump and booster pressure sensor water levels

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