If you could program any sequence of wash drain rince cycles for a Dishwasher what would it be?

[777funk]

I've never thought much about this until acquiring an old Kitchenaid Hobart. I noticed that it has very short sequences after someone here mentioned it and I finally paid attention. I don't think the sequences make sense (to me anyways).

'Normal' does the following:
-drain for a minute or so
-fill
-heats the water for about 5-10 minutes
-Prewash for 1.5 minutes no detergent
-drain (bye bye heated water)
-fill
-Prewash for 1.5 minutes with detergent
-drain (bye bye detergent)
-fill
-rinse (I think)
-fill
-Wash for 1.5 minutes
-drain / fill
-Wash for 5-10 minutes with detergent (stopped paying as close attention at this point
-drain/Fill/Rinse
-drain/Fill/Rinse
-Non Heated dry

If I were to redesign this (as if I know more than KA engineers)... I would do the following:
-Drain
-Fill with enough water to pressurize the sprayer arms plus a residual on dishes plus a margin of error now plus a margin of error when the lines get caked from hard water (or better yet use a float valve as the fill level)
-Heat to a set temp of 155F (sensor)
-Run this water for 3 minutes without detergent
-Drain / Fill
-Heat to 155F
-Run this water for 3 minutes without detergent
-Dump detergent
-Continue pumping with this water for 20 minutes
-Reheat (probably too much for a 15 or 20A circuit to run pump and heat simultaneously)
-Pump this water for 20 minutes
-Drain / Fill / Rinse
-Drain / Fill
-Heat to 155F
-Rinse
-Drain
-Air Dry

This would be easy to program into a microcontroller. It wouldn't be as easy to wire it all up and fit into the space in the machine. Actual sensors would also add much more complexity than just timers. It would be an interesting project if time ever allows. I'm sure it's been done. The result would be a very nice dishwasher no doubt. Maybe even an energy efficient one.

 

[combo52]

KA KDS-19 Cycling

Hi Nick, You are correct that the cycling sequence that KA used made little sense, Maytag reverse rack machines were also not very logical in their cycle sequence. Best DWs in this respect were Whirlpool from 1958-1998 and D&M from the early 60s through the early 80s.

 

There are also a few others that did a good job of cycle sequence design.

 

A couple things to consider, your KA DW has three places for detergent, when you put detergent in both cups and close them you are supposed to put some detergent in the recessed area above the cups. [ I believe you should never start a DW cycle with no detergent in the first water fill ]

 

I also believe KA was stupid to heat the first fill, instead they should let the first fill warm up the machine and dishes in the pre-wash and then heat the main wash and last rinse. It is also much more productive to heat water while the main pump is running, why waste time and heating water in the sump NEVER raises the entire dish load to any set temperature.

 

I completely agree that all DWs should have had metered fill, if they had done this they would have solved millions of DW complaints and problems.

 

John

 

[777funk]

If not metered fill, at least enough sump to have pressure with far less than designed water quantity.

Then again, after 10 years, the manufacturer counts on the user to buy a new one. So maybe the engineers are doing exactly what they were paid to do with low water quantities and pressure as time passes.

 

[iowabear]

When I first got my "modern" (2010) WP dishwasher I didn't like that it only filled 3 or 4 times.  I was so used to the older models that filled and drained far more often.

 

But it cleans better and still rinses the dishes clear.

 

I think the removal of phosphates from DW detergent makes things harder for the old machines.