Main Wash time comparisons between new vs. older dishwashers

[murando531]

Hello all,

Out of curiosity I decided to time my PowerClean's wash time myself with a stopwatch, and I was surprised to learn that on the Normal cycle with no options, the main wash itself is only 12 minutes!? I always knew these machines had short washes compared to most, but I thought it was at least between 15-20 minutes. Adding the PowerScour option instructs the machine to do a temp hold on the main wash, which ends up being around 25 minutes, but it also adds a full rinse before the heated final rinse rather than a purge. I know this sounds crazy, but I always sort of liked the fact that the PC cleans and rinses so well while only having one full rinse. I wonder though if 12 minutes is long enough for the detergent to do its job and for the enzymes to activate and perform correctly. So far just using Normal seems to be fine on everyday soil, unless of course it's been cemented on after a day or two of sitting.

It made me wonder: how long is the main wash on newer dishwashers today on a Normal no options added cycle? I know my Maytag's is at least 30 minutes, but I haven't been able to "admire" anyone's new machines long enough to know how long other brands run. And is the 12 minute wash long enough for today's detergents to work, whether it be Cascade/Finish tabs or pods?

 

[mwb]

Andrew,

I have a Miele Professional dishwasher. The Normal (Universal) cycle on mine takes about 30 minutes in total with no cycle alterations. Everything, including stuff with two-day old dried on food, comes out spotless. I never have to rewash anything. I use Oxiclean Extreme powder (full of enzymes) so apparently the enzymes must be able to work fairly quickly.

My owners manual advised not to use pods/packs as the cycles are too short for them to dissolve properly. Since your wash cycle is so short, it's possible some detergent might carry over into the rinse. You might want to check that out.

Mark

 

[murando531]

Mark - Your entire cycle is just 30 minutes? That's impressive for a newer machine. If so, that makes me feel better about using the Normal on this one. I actually did open the door and tried to fish around for any remains of the tablet, but I couldn't find the trace. I'm using Finish Quantum tablets currently, and the water actually had a little red tint to it because of the red rinse aid section. I let the machine continue through the purge and beginning of the final rinse, and I opened it again to check the water - crystal clear, and even felt squeaky clean when I rubbed the door and the wash arm, so I'm assuming the detergent is having no problem dissolving. My main concern is the effect of the detergent during that time.

 

[logixx]

Your entire cycle is just 30 minutes? That's impressive.

The Miele Pro models aren't just your average dishwasher. Though they look like and have all the features of the residential line, the heater draws almost 5 kW, the pump recirculates 50 gallons per minute and the Sani cycle goes up tp 185°F.

Depending on the cycle, my Bosch takes 25 to 40 minutes for the main wash.

 

[behzad]

Yes, I agree with you

actually my Fagor takes about 15 minutes to does the job,
the circulation pump ~40 or 60 W (I'm not sure) and It using the pump to spray both racks at the same time, but Bosch and most of the other newer dishwashers using alternative-spraying which much quieter than something like mine!

and yes, I agree with you. the average wash time became shorter these days, thanks to better heaters, quieter pumps and thinner nuzzles on sprayers

 

[Chetlaham]

Power cleans had short normal washes if the Thermal hold was skipped or water was hot enough.

Generally older machines had a short normal was of 10 minutes which grew to about 20 minutes in the 80s then to 30 minutes and eventually to over an hours on tall tub energy saver machines.

These a rough values but in a nut shell they all have grown in time, even with the same mechanism. Whirlpools Dura washes started out short and grew longer, same with GE where an 18 minute wash turned to a 50 minute wash in the mid 2000s despite similar motors.

 

[henene4]

Our Bosch varrys a lot. On Eco, the main wash takes up to 100 minutes I think (Barely using this cycle).
The Intensive cycle has a 20 minutes pre wash, and about 50 minutes main waash. Just roughly.
Most exactly I know the Auto cycle. It either does a 15-20 minutes pre wash and a long 70 minutes main wash or no pre wash and a 50-60 minute main wash.
@logixx Really? 40 minutes maximum? That is about the shortest main wash on the Auto cycle. And on Eco, yours definetivley washes longer....

 

[mwb]

Regarding short cycle times of vintage machines

We must remember that enzyme based detergent is a relatively new phenomena. Back when automatic dishwashers were gaining in popularity, detergent for said dishwashers were full of phophates and sodium hypochlorite ( dry chlorine bleach ). To clean properly, dishwashers relied on moving a lot of water under a great deal of pressure. That water had to be relatively hot for chlorine based detergent to work well. It wasn't uncommon for residential water heaters to be set to deliver water upwards of 160 degrees.

To reach at least 140 degrees during the wash cycle, older units had a series of relatively short prewashes/prerinses to essentially pre-warm the wash cabinet and the dishes. While this worked extremely well, it also required a great deal of water. The energy crisis during the seventies had consumers turning down their water heaters to 120 degrees and with the eventual introduction of enzyme based detergents, set us on the path to where we are today.

Some of that is a good thing and some is not. I personally am glad to see the demise of chlorine based detergent. While chlorine is highly effective, it is also very corrosive. One only need look at some of the vintage machines of the '50s - '70's today and it is quite evident how damaging long term use of chlorine is.

 

[washerdude]

In our new kenmore for the 1 hour wash the main wash is 14:49 timed and the normal wash main wash is 30 minutes with no additional options enabled.

 

[launderess]

Chlorine bleach will work for both disinfection, stain removal, breaking down protein, etc.... in warm or even cold water. It will take more time than hot but nothing requiring hours to wash dishes.

Hot to very hot water is needed for washing dishes especially in automatic machines in order to ensure breakdown and dissolving of grease, fats, and oils.

In the early days of automatic dishwashing detergents you were dealing with mainly phosphates, washing soda, dry chlorine bleach and some surfactants. Until modern low foaming surfactants came along with properties suited to automatic dishwashing you needed hot (140F to 160F) water in order to ensure proper removal and suspension of grease etc....

As detergents improved that temperature came down to 120F to 140F with higher reserived perhaps for "pot scrubbing". The introduction of enzymes and even better surfactants means the job certainly can be done at 120F and lower than 140F since above that temperature is when enzymes become deactivated.

My GE Mobile Maid will clean very well with modern dishwasher detergents with 120F water temps. In under one hour everything is clean. However without the residual heat from blasting dishes with 140F or above water drying suffers unless you use heated.

I can tell dishwasher detergents today are more powerful as loading the detergent cup *twice* (as recommended in the GE MM manual) causes all sorts of problems. Now only use a teaspoon in the first wash and fill the cup half full for the main. Probably could get away with not using anything in the prewash but never liked the idea of gunk filled water being splashed all over my dishes and inside the machine.

 

[logixx]

@henene

Yes, 40 minutes max - when using the varioSpeed (Speed Perfect) mode - I almost never use the regular mode, which would probably extend the main wash to similar durations as you have mentioned. Can't comment on the Eco cycle as I have never used it since I got the dishwasher (two years ago).

 

[jerrod6]

I actually never use the cycle named normal on my machine because it does 2 pre washes and then washes and rinses like forever and cleans no better than shorter cycles while using more water than almost any other cycle on the machine.  Instead I use the sensor(automatic cycle) which varies the wash time between 18 minutes and 1 hour 16 minutes depending on soil level, incoming water temperature and load size.

 

When I don't use that cycle I use another cycle that has a main wash and two rinses.  In this cycle main the wash lasts 34 - 45 minutes depending on incoming water temperature. In the winter my incoming water temperature is about 61F for the pre-wash  portion and 93F for the main wash, so I guess in a cycle without a pre-wash the incoming  water temp is 61F for the main wash- this gives the 45 minute main wash.

 

[washer111]

I'm starting to feel like a stuck record saying this... But for the record:

We use the "Delicates" cycle on the DishDrawer, for a number of reasons:
- The Normal cycle never actually washes for as long as its supposed to, shaving about 10-20 minutes off the wash time. Delicates is What-You-See-Is-What-You-Get - a 26 minute wash, 2 12 minute rinses and a longer final rinse
- Its the only cycle where the final rinse temperature WILL reach the published spec. when the inlet is cool/cold. All the other cycles seem to time out, even with moderately warm water several degrees below where they should (I've observed this using the DD's diagnostic mode sensor that displays the temperature)
- Three rinses: I don't like the idea of just two or (heaven forbid) one rinse (which this machine doesn't have). The third rinse ensures all residue is flushed away

If we use a heavier cycle, its always the Heavy/Heavy-Eco cycle, which washes quite a lot hotter and about double the time of Delicates. We generally do this about weekly to help keep the filter clean, since we don't rinse our dishes, and they aren't scraped well either.

 

[rolls_rapide]

What Launderess says is correct.

I have found that my 2004 Bosch which has 2hr programmes is VERY fussy with its spray arm pressure and the length of time a particular basket gets sprayed, i.e. 50 seconds! And in some cases, less, because the sensors reduce the spray to a trickle, checks the clarity and reverts to the lower basket again. Sloppy programming, methinks.

The modern tablets and enzyme detergents will not remove persistent tea and coffee stains from my mugs. Yet one wash with a chlorine based dishwasher detergent removes all trace of the stains, and stainless steel pots and pans positively gleam.

I notice that my mum's 2014 Bosch dwells much longer on a particular basket, and in general, gives superior spray arm performance with tablets.

 

[henene4]

Phosphate

I somehow feel guilty after I recognized that our DM (a german drug store) tablets contain about 30% of phosphates. Quite a lot, I think. But they work flawless. And are surprisingly cheap. Maybe due to being used in a slim line DW. Any tablet works on a slimline, simply due to smaller loads and less water.
But the contain a good amount of oxygen bleach, too!
Our 2012 slim Bosch as well usually spends a minute or 2 on each basket, depending on cycle and cycle step. But as it is a one speed motor, there is no pressure variation.

 

[logixx]

Rolls - have you tried the speed mode? It washes both both baskets at once. Our 2004 Bosch would usually go through the full range of spray pressure during its auto cycles.

Henene - a 2012 BSH without BLDC drive?

 

[jerrod6]

As far as I know you aren't going to go into a supermarket, or big box store in the USA and find a DW detergent containing phosphates, so as well as they might clean, they are not available to most people in the USA.  I don't see any DW detergents with Chlorine bleach either.  It use to be that Finish powder contained this, but in the last year or so it has been reformulated to contain enzymes and the chlorine bleach is gone.

 

I guess you may be able to order some type of institutional CB DW detergent but the majority of people in the USA are not going to do this, so for most in the USA there is no easy CB DW detergent option.  It's gone.

 

[launderess]

German Dishwasher Detergents

Read somewhere the reason for German automatic dishwashing detergents being loaded with phosphates is due to quality of the water. Apparently you've got some very hard stuff in that country thus the need for phosphates.

IIRC the article was written by someone from one of the detergent makers in response to the recent changes in the USA market; that is P&G along with most others getting rid of phosphates.

As with laundry detergents it is possible to formulate automatic dishwasher detergents without phosphates but it is tricky, as P&G found out when their new Cascade bombed. Again as with laundry detergent it takes several chemicals to replace just the one (phosphates) and results can be off until the formula is tweaked properly.

 

[murando531]

In light of those responses, with the new formulas in modern detergents, are they still effective in machines that have relatively short main wash periods? Most specifically in tablet/packet variations. It seems that most all powder detergents are the companies' most basic varieties: results with standard Cascade or Finish powder have been reviewed as terrible in recent years but they would be the choice for the quickest dissolve time. The detergents that work well, such as Cascade Platinum or Finish Powerball/Quantum tabs, are the ones that are more densely packed.

I did check my machine about 4-5 minutes after the detergent cup clicked open, and I couldn't find any trace of the Quantum packet, so unless it had gotten stuck somewhere between the coarse grate and the grinding plate, I'd assume it mixes quickly. I just wonder if that 6-8 minute time after it has dissolved is long enough to be effective on a typical load of dishes without wasting detergent down the drain.

Of course I can always just add the PowerScour option, or use the Heavy cycle, both of which actually temp delay the main wash to 140F, and then continue for a bit of time afterward. That puts more wear and tear on the element and the electrical components though, along with using more energy, both of which I'd rather not have to do unless necessary.