Thread Number: 77081
/ Tag: Vintage Dishwashers
Last Ditch effort to see if someone can help me with my KDM-21 |
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Post# 1010158   10/8/2018 at 21:53 (2,026 days old) by joeypete (Concord, NH)   |   | |
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As in my previous post, I still have my KDM-21. I had purchased a new Bosch but the installer failed to contact me and after looking at my Hobart, it worked fine so I figured I'd keep it...and cancelled the order.
It has worked fine for the past 3 weeks until the other night when I started having issues again. Tonight I ran a full cycle...meaning from start to finish on the timer. The Soak and Scrub cycle. From what I noticed, the machine is having issues with draining. Every wash segment ran perfect. Here's an overview of what happened: Start of Soak and Scrub...pump came on like it was supposed to...filled with water and washed. After it filled it shut off to heat the water like it should. After heating it washed for 3 minutes as it should...heated the water again...washed for 3 minutes. It then began to drain and the motor shut off. The timer kept ticking away. I didn't touch anything. It got to the point where it would fill again for the first full wash segment. The tub was mostly full of water so it filled until the float stopped it....the timer kept ticking and it was a bit before it switched over to water heating mode. Very brief heat period and the detergent cup opened. It then washed the full 10 minutes with no problems. Again it went to drain, motor kicked in for 1 or 2 seconds then stopped. Timer ticked away until it was time to fill again for the first rinse. It filled to the full amount then began washing like normal for 5 minutes. Stopped and began to drain. This time it drained completely. All normal to next fill for the main wash segment. Began washing, the detergent cup opened. It washed for 10 minutes no problems. Drain after this was also successful. Next it filled for the final rinse. Motor ran for the normal 5 minutes no issues. It stopped, began to drain and same thing as earlier, it stopped after a second or 2. I let the machine continue to the dry portion. When the fan kicked on I hit the Cancel button. It did not drain the water out...the motor never kicked in. I opened the door to reset the timer and hit Cancel again. It did not drain the water again either. I let it sit for several minutes and tried Cancel again. This time it drained the water completely. So from what I can tell the machine is failing during the DRAIN segments. So I have to figure out why it's having issues draining. More specifically why the motor is actually shutting off when it goes to drain. Going back a few months before this started, I began to notice a loud gurgling noise coming from my sink drain when the machine was washing. My machine drains into my garbage disposal. I did research and read that the check valve can go bad ( the thing with the rubber flap in it, I think this is the check valve?). It no longer makes any gurgling noises. So first question is if the check valve has failed, would that cause the machine to actually stop the drain process or would it continue to try and drain but no water would get out? If it does not stop the motor, then what other component should I be checking that controls the drain portion? Could the timer be at fault? I don't even know if this machine has a drain "solenoid". It doesn't seem like the motor is bad if it's washing ok, right? I dunno. I really appreciate everyone's help. As excited as I am to get new appliances, this dishwasher has a spot in my heart and I've had a huge amount of anxiety with the idea of having to get rid of it. So if anyone could help I would be very happy. Thank you very much! |
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Post# 1010161 , Reply# 2   10/8/2018 at 22:55 (2,026 days old) by joeypete (Concord, NH)   |   | |
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Stevet! Thank you so much. I was hoping you'd respond since you are the Hobart expert! haha
When the motor stops after trying to drain, I don't hear anything. It just shuts off. As far as the water flow...yes it goes out with quite a bit of force. When it was draining, I looked down the disposer and the water was coming out at a good clip. It didn't take long to drain at all. I'll take a look at the internals of the pump to see if anything is stuck. I had to take it apart a while back when I made my interior view videos....when I discovered that the lower spray arm wasn't moving hardly at all! It was really dirty and gritty. Hopefully I didn't mess anything up when I took it apart. Where exactly is this elbow you are talking about? I just want to make sure I find the right area. Thank you again for your help! |
Post# 1010189 , Reply# 3   10/9/2018 at 07:44 (2,026 days old) by joeypete (Concord, NH)   |   | |
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I took off the the components down to the drain impeller and I did not see any blockages. I did pull out a small piece of ceramic, but it was in a channel and not near any drain area so I don't think it was an issue.
After I put it back together the spray arm doesn't spin as freely though...it spins then stops. Is that normal or should it spin freely? I just don't want to happen what did last time and the arm wasn't spinning during the wash. Maybe I tightened the wash impeller too much? (Edit...it does seem to spin pretty well. If I spin it, it will go a few times around then stop. It just felt a bit tight. Before it was spin really fast is all). I also ran a Rinse/Hold again and it ran without issue. I then hit Cancel and it drained without issue. My next wash is tomorrow night so I'll see how it goes. If not then: I guess the next step would be to replace the program switch and start relay to see if that helps? If you have either of those parts I'd be happy to buy them off of you Steve. According to my parts diagram the relay is part number 242745 and the program switch is 242489. My switch has the 3 wash buttons and then 4 option buttons. Let me know your thoughts...or anyone else for that matter. :) Thank you! This post was last edited 10/09/2018 at 08:12 |
Post# 1010197 , Reply# 4   10/9/2018 at 09:59 (2,025 days old) by combo52 (50 Year Repair Tech Beltsville,Md)   |   | |
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Hi Joe, you likely have a main motor problem.
You can try changing the motor start relay as Steve suggested, but I would start by checking the resistance of the motor windings, the wash winding and the drain winding should be the same, also check the run main winding for proper resistance and any shorts to ground. John L. |
Post# 1010198 , Reply# 5   10/9/2018 at 10:06 (2,025 days old) by joeypete (Concord, NH)   |   | |
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Post# 1010204 , Reply# 6   10/9/2018 at 11:48 (2,025 days old) by combo52 (50 Year Repair Tech Beltsville,Md)   |   | |
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Post# 1010208 , Reply# 7   10/9/2018 at 12:49 (2,025 days old) by joeypete (Concord, NH)   |   | |
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Post# 1010382 , Reply# 8   10/11/2018 at 08:34 (2,023 days old) by joeypete (Concord, NH)   |   | |
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So the other night I took off the lower panel to inspect. I didn't see any signs of burnt wires or anything else "bad". I took off the start relay and cleaned the wires and connectors and also took off the ground wires and cleaned those and reinstalled. Looking underneath this thing you would never guess it's 33 years old. It's very clean! Very very little dust on the motor but I did wipe off what I could.
Last night I ran a Light Wash and it did perfect until the final rinse. Started to drain then stopped. Again the Cancel feature didn't work right away either...at least the drain segment. I let it sit for about 15 minutes and tried again, and it drained. This morning I ran 5 Rinse/Hold cycles right in a row and it did not fail once. Filled, washed, and drained perfectly each time. Now I'm certainly not an expert but it seems weird that it can't get through a wash cycle without failing but it can do 5 Rinse/Hold's right in a row without issue. To me that sounds like something is wrong in either the timing or the program switch. One thing I remembered was over a year ago I ordered some butyl mats to put on the door to reduce noise. I also put some in the control panel area. Like a moron I forgot to turn off the power and my screwdriver hit the program switch and sparked. (It's also scared the bajeepers out of me). Obviously it wasn't something catastrophic because it's worked fine up until now. But perhaps it caused enough damage that it's deteriorated over time. So today I'm going to take off the control panel to inspect. Perhaps disconnect the program switch and clean it and use some silicone spray on the buttons. I think I'm going to get a new program switch anyway. I found an NOS on ebay for cheap so might as well try. I don't know how this machine works exactly but maybe there is an issue on the side of the switch where the wash programs are...and perhaps the Cancel is connected to those? Again...I'm just brainstorming and trying simple things before I decide to replace the motor. Any thoughts would be appreciated! Thanks again. |
Post# 1010424 , Reply# 9   10/11/2018 at 14:16 (2,023 days old) by joeypete (Concord, NH)   |   | |
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This might have something to do with it. :-/ It’s on the Normal cycle button. Also the purple wire next to it was unplugged!
Any way to fix this?
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Post# 1010425 , Reply# 10   10/11/2018 at 15:21 (2,023 days old) by joeypete (Concord, NH)   |   | |
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Also this ground wire was completely gunked over.
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Post# 1010489 , Reply# 12   10/11/2018 at 20:38 (2,023 days old) by joeypete (Concord, NH)   |   | |
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I ran a Light Wash tonight and it completed the whole cycle! Hopefully that was the issue haha. I'm thinking that maybe that purple wire was loose and when I pulled the switch out it came off. Weird that it would be loose, they aren't exactly easy to get off! But something worked tonight. :)
If it keeps working ok, I'm going to replace the drain impeller gasket...the one that is underneath the silver U shaped plate over it. It was completely trashed when I took it apart. Yes I plan on getting the new switch too. Like you said, not a bad idea to replace it. Especially while I can find parts. Thank you again for all your help. :) |
Post# 1010537 , Reply# 13   10/12/2018 at 13:04 (2,022 days old) by johnb300m (Chicago)   |   | |
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