Descaling dishwasher

[suburbanmd]

About descaling a 1999 Kenmore Ultra Wash dishwasher -- How much citric acid would you use? Could any harm come from descaling dishes at the same time? I suspect our drinking glasses, in particular, could benefit from it. They're made of Tupperware, hard plastic of some sort, or glass.

BTW, I used Miele "Descaler for washing machines" to descale my Miele W4840. It looks a lot better now. The box says "Contents: Citric acid", so I guess that's all it is, 250g of it, at a price I'm embarrassed to mention, but you can find it online if you're interested. Now I bought 5 lbs. of food-grade citric acid from Amazon for $27.49.

 

[whirlpolf]

citric acid

hi Suburban!

Fact is: Anything sour will descale objects. But I had tried vinegar and even concentrated vinegar, chemical descaler based on formic acid and citric acid as well.
All except the citric acid were able to remove the nickel from nickel plated heating rods or nickel coated heater elements (result: the copper tube that they are made of has contact with the water, the poisonous green stuff now goes into your kettle water / tea water).

My guess is an "ok" for citric acid, even overdosing did not do any harm in kettles, washers or on immersion heaters. Try to get them in no-name packages at foreign food stores. My experience is: Miele descaler = some 19,- Euros, any no name descaler (citric acid based) = 4,50 Euros per pound, pure citric acid (food grade) in turkish/russian/italian/mexican specialty places= -.50 Euros per pound. I guess they use it as a substitute for lemon juice, no idea.

Dosing it 1 tablespoon per liter should do, I think.
Prices may differ overseas, my sermon refers to Germany, no idea for your area.

Good luck! ;-)
Joe

PS: There may be wiser ideas, this is just my 2ct to it.

 

[awooff]

Sounds as though you could benefit from a water softner, and the newer dishwashers will provided better much results as well.

 

[mysteryclock]

I've used both Lemishine (which IIRC is mostly citric acid) and the Dishwasher Magic product (15-40% citric acid according to the MSDS) and both have worked wonders keeping the nasty grey flaky scale off the SS tub of my KA dishwasher. I've used full prewash and wash compartments of Lemishine to descale glasses (real glass ones) and SS silverware with good results, but I'm not sure what any descaler would do to plastic glasses.

The Dishwasher Magic I use solo.

Perhaps you could figure out the volume of the DM package and calc out what 30-40% of that would be in citric acid and try that? Or just start with a teaspoon in each dispenser compartment and see if the gunk comes off with that, and double & repeat until you get to a good level.

 

[stevet]

Try oxalic acid!

Many years ago, Kitchenaid recommended using Oxalic acid to remove rust and iron stains from their porcelain tanks.

You can purchase it at most big paint stores as it is still used to treat rust stains on siding and concrete

I believe it was like one teaspoon in the main wash dispenser and run it thru the cycle and then one cycle with detergent.

Our water was extremely hard and we had measurable limescale on the rack that you could chip off. Needless to say the glasses always looked like they had milk on them.

The Oxalic Acid not only removed the scale and any rust/iron staining, but it cleaned the glasses as well. We had to repeat it periodically and the machine lasted many years without any damage to the interior parts ot the element in the sump.

Once the City of NY condemned the water company and pumped in soft water, the lime disappeared all by itself from the racks and the machine cleaned incredibly well!

The bottom line, Like Awoof mentioned above, you are in desperate need of a water softener. If your dishwasher is like that, your plumbing fixtures and hot water heater and washer must all be looking pretty beat up if not on the outside, they surely are on the inside.

This is not a reflection on you personally, as I am sure you realize, but the reality id most Americans are in denial of the need for this item. We look at the initial cost but forget the costs thru the year on trying to get and keep things new and shiny and to prevent premature wear and tear.

 

[suburbanmd]

I don't want/need a softener

Whoa, my situation isn't as dire as all that... The hardness in my water is dissolved calcite from an acid neutralizer, and it isn't all that hard. My 10-year-old dishwasher has no visible scale on its plastic tub, or spray arms or spray arm holes. I got on this descaling kick because my Miele clothes washer (less than a year old) started to show some visible scale on parts of the stainless steel drum, and the glass door. When I saw how much better it looked after descaling, I figured it couldn't hurt to do the dishwasher too, because there must be some buildup somewhere. And drinking glasses are somewhat dulled and could probably benefit.

Thanks for the info on citric acid and related topics. Apparently Miele isn't too worried about overdosing either -- if 250g of citric acid is enough to descale an older machine that uses lots of water, it would be more than enough for a newer machine.

 

[mysteryclock]

One other thing

It took me a while to get the grey scale off the SS drum of my Bosch FL, using a variety of things including citric acid. Once I did I've kept it away by using a full fabric softener compartment of vinegar with each load of clothes. Works great rinsing the clothes and has kept the drum shiny clean. I know the vinegar is doing that because there was a little bit of scale left after all my efforts and it gradually went away once I started using it.

 

[andrewinorlando]

My LG dishwasher developed a serious scale problem which LG attributed to the detergent tablets combined with the moderately hard water I was using. The filter, which is located under the lower wash arm, almost completely calcified, actually making the filter screen hard. Once that happened, water was unable to pass through the filter and would wash backwards into the pump and circulate over the load. This was causing the sensor to malfunction as it wasn't reading the soil level correctly, since it was being passed back into the circulating water stream. Needless to say, it produced dirty glasses and other items. Since the sensor controls the machine's wash temperature, it kept sensing a clean load, and would set the wash temp at only 95 degrees, hardly enough to clean dirty dishes. I had to switch to the pots/pans and soak cycles to get the machine to do a half way decent job.

Once I found the problem, I used CLR to descale the filter and pump. The machine itself had no scale buildup, only the filter screen. I poured a small amount of CLR right onto the screen surface (you cannot disassemble the LG's filter - it's a one piece unit). I let it sit, then started the machine and added some more CLR to the water and let it wash.

That did the trick perfectly, and the machine is back to washing like it did when it was new. LG said the detergent tablets are far too concentrated (i.e., too much detergent) for the smaller amounts of water the machine uses, and you only need half that amount for the average very dirty load. I wonder how many other HE machines have suffered the same fate without anyone knowing the difference because their filter screens are not visible like the LG's, and service techs don't know what the hell to look for when a machine developes cleaning problems??

Lesson learned - almost the hard way. I was ready to pitch the machine after just one year, but it's back to normal again thanks to CLR!!

 

[mrsalvo]

I use Limeaway. Run a cycle with no dishes. Cleans it right up.

 

[andrewinorlando]

Barry, where do you find LimeAway? I looked at the supermarket, and even in KMart, and could not find it. Also didn't see it at Home Depot or Lowes.

 

[autowasherfreak]

I think Wal-Mart and Walgreen's drug stores sell LimeAway. CLR is good too.

 

[suburbanmd]

LimeAway

Google search for Limeaway found some references to it discoloring stainless steel.

 

[gyrafoam]

1/2 Cup of Sno-Bowl into the main wash and let it complete the whole cycle. Works great for me.

 

[suburbanmd]

Scary

A dishwasher is a lot more complicated than a toilet bowl.

 

[kenmoreforever]

CLR puts limeaway to shame when cleaning iron deposits on sinks and the sort.