KA KDSS-21 Questions

[mieletag]

Hello folks.

First time poster, long time lurker here. Thanks for such a great site!

I might have the opportunity to acquire a KitchenAid KDSS-21. The only problem is the heating element is bad and it shorted to ground and took out the thermal protector with it. Now, the computer, rapid advance timer, bi-metals, rinse aid dispenser and flow through heater/blower work fine. I went into diagnostic mode and ran all the tests. Works perfect otherwise. From the schematic, I take it that the sheathed heater has two elements inside,one end having two terminals, and the other having the single common. The current owner has not been able to use it for several years since they had a repairman to look at it. He wanted to sell a new one, so he cut the thermal protector out, took it with him, and left it disassembled.

Now, the questions I have are: the two other thermostats that are connected to the shielded wire; how does that control the two heaters? Does it have 12v that sends a signal to the computer and then advances the rotary switch to shut off the heating elements in sequence? Surely the computer doesn't directly control the heating elements through any kind of triac. (I didn't see any on the board, I just saw a SPST open relay on the board.)

Also, where can I source a new heating element and thermal protector? I haven't had any luck finding any on-line so far. Also, the little sprung plastic cam that is attached to the door latch shaft that pushes in the momentary tact switch on the board is broke. I would be more than happy to pay whatever it takes to get this great machine going again.

Thanks so much

Chris

 

[mieletag]

Also, at the bottom by the pump, there is two nylon disconnects, one is to the reversing pump motor. The other is just dangling, nothing is hooked up to it. Just a two pole connector with a single white and black wire going in, coming from the upper control panel. The repairman cut the white wire going to the fill valve labeled PRT. The other cut one is the black wire with the guarded right angle connector going to the single terminal on the heating element assembly. This one is labled WH. I'm assuming the white wire was hooked to one terminal on the thermal protector and the other black wire was connected to the other side of the protector, thus completing the circuit. But that still leaves that lone two pole connector.

 

[rp2813]

Wait for Steve T. to show up.  He should be able to provide the answers you seek.

 

[combo52]

KDSS-21 KA DW

This was the 2nd KA DW that was electronically controlled, I am very familiar with this DW as we were doing factory sales and service on them when they were being sold. I have the full factory manual here in our files.

 

The dual heating element is the same as the heater in the 18-22 DWs that had the sump heater so even though it is NLA it should not be hard to find [ we have both new and used ones ]. The thermistor in the sump controls the heater through the computer board which in turn advances the rotary power controller that actually handles the high current for the motor, heaters etc.

 

These machines were very cool but had lots of problems and I do not know of any that are in regular use any longer, I do have lots of used parts for these if you want to take a chance on fixing it.  John

 

[mieletag]

Yes, I would be very interested in parts to get this machine working again. It really intrigues me how it works. Do you think relays controling the components and the relays being switched from the rotary switch would be better since the rotary switch would not be switching high inductive loads like the motor? But then you would probably need a another snubber for the relay coils.

Thanks!

 

[combo52]

KDSS-21 KA DWs

The rotary power switch is just like a timer in a non electronic KA DW, it will be the LEAST of your problems with this DW, it is about the only electrical part of these DWs that I never saw a problem with.

 

[mieletag]

Looking at the Singer computer board, it looked like it was fairly straightforward, other than the ICs. Could put a few MOVs in. Do you know if a latch actuator would be available and what temperature the thermal protector opens at?

Thank you so much for all the information. I guess the 23 series had the pump and electronics from Whirlpool. Looks like the KUDA23 Selectras have relays behind the vacuum fluorescent display. I guess Hobart was still caught between the mechanical rotary switch and computer control, kind of a hybrid of sorts.

Don't worry, the daily driver would still be my Miele LOL.