Rust in Dishwasher?

zarkbuilder · May 11

We have a pink/red/brownish coating on interior of stainless steel tub dishwasher. We read this may be rust , but are not sure.

We clean the greasy feeling coating with dry paper towels when cycles are complete. We have used 'lemon' cleaner in an empty DW , but the result is less than effective. We have not used CLR, yet. DW is top end USA company about 10 years old. Dishes come out very clean 95%+ of the time. We are the original owners of this 20 yo House with 'modern' plumbing and copper pipes everywhere I can see.

DW water supply is short from water tank. Good (I think): all running water is clear from all other faucets. I plan to do a 'still' water test soon. Bad (maybe): the pot filler faucet over the stove will have a tendency to release a two cup (?) amount of rusty water upon opening, then water is clear. This filler faucet is used about every two weeks. The pot filler is further away from the water supply (or farther downstream of the DW) by about 10-15 'pipe' length feet. We did not connect the two issues (pot filler rust and DW discoloring) until now. I have not yet traced the potfiller pipes to see if they are downstream of the DW. There is no discoloring in sinks or tubs anywhere in the house. City water supply. (edited)

Qs: Can rust be a possible culprit inside the DW? If almost all pipes are copper, what pipe elements (t-joints, valves, DW components, etc..) might create rust? Thank you for your suggestions.

hot_rod · May 11

On a city water supply? In spring, early summer water from most any water supplier has higher turbidity. Sometime called the optical clarity of water since the particles are so fine.

Fill a clean glass with cold water let it sit overnight. That will tell if it comes from the water supplier.

If it is clear, try the same with a glass of hot only water. That would tell if the water heater is the problem.

mattmia2 · May 11

if the film is greasy it is minerals in the water making less soluble organic salts with the detergent. frequently running a cycle with citric acid in the detergent cup will dissolve it and clean it off.

JUGHNE · May 11

Wouldn't the pot filler be cold water and of course the DW supply would be hot water.

mattmia2 · May 11

the pot filler is probably screwed in to a drop ear ell with a galvanized nipple or something like that, it probably is unrelated.

zarkbuilder · May 11

https://forum.heatinghelp.com/discussion/comment/1896299#Comment_1896299

Yes, that is correct. usually, we will finish cleaning the sink area at night, then immediately run DW so that it pulls hot water immediately. Not always, but usually.

pecmsg · May 11

Try rust remover in the bad area. If it works look for galavinsed pipe.

EBEBRATT-Ed · May 11

How old is the house approximately and how old and what type of water heater do you have?

ChrisJ · May 11

https://forum.heatinghelp.com/discussion/comment/1896331#Comment_1896331

This made me think of "who's your daddy? Is he rich like me?".

No idea why but I'm sure you'll recognize the lyrics.

mattmia2 · May 12

you could also install something like this on the inlet to the dishwasher:

https://www.supplyhouse.com/Nuvo-H2O-CITRAPRO-Dishwasher-System

hot_rod · May 13

you mentioned the pot filler, is it a cold water only, or is it a mixer blending H&C?

If it is connected to just cold, and you get rusty water there, it is probably not related to the hw or piping.

Look for a galvanized or steel nipple on the water main, maybe at a PRV where it enters the building.

A whole house rust and sediment cartridge filter would handle anything from the water supply entering the home. But if the cause is inside the home you need to track down the source.

mattmia2 · May 13

i looked at the instructions for a couple pot fillers and they screw to a nipple sticking out of the wall like a tub spout or wall faucet. i suspect that they just used a galvanized instead of brass or stainless nipple to come out of the wall and you are seeing rust from that nipple.

zarkbuilder · May 23

Hi Folks,

—First, thank you for your suggestions. Pot filler is Cold only. City water, though a long distance, but still City water supply. Still cold and still hot water test produced zero particles from sink faucet above DW. magnet drew zero particles. magnet inside DW had zero particles attached at cycle end.

—Pot filler is behind a beautiful tiled wall (of course). I will be 'removed' before the tile is ;-)) I will attempt to locate tools to remove pot filler and will report back in the future. I did notice that the last pot filler 'junction' (in basement) is a 3 way junction (not a 'T') at odd angles. I can not confirm the ending of the 3rd pipe. working on it.

—DW film is greasy. Difficult to run a 'clean' cycle since DW is completely filled nightly (and sometimes we fill the second DW in the basement). I had a rare opportunity today with offspring out of the house. Just completed using a Cscd Platinum Dishwasher Cleaner packet and the grease was more noticeable and more pink. Summary: no effect or worse looking. Next opportunity will be to run a distilled vinegar cycle with Lemishine powder in tray. I will report results in future.

Thank you for your advice

mattmia2 · May 23

are you sure it is draining properly between wash and rinse? are the screens clean? (rant about noise testing pushing mfgs to make this terrible design choice redacted)

Intplm. · May 24

You might need to condition or at least filter your water at your water main. It wouldn't be the first time that it's been done on city water.

Jamie Hall · May 24

"DW film is greasy". Ah… no. If the dishwasher film is greasy, rusty or not, you have a problem with the dishwasher itself, not the water coming into it (unless that water is greasy, which is beyond unlikely). Most likely not fully draining, but there are other possibilities.

It goes without saying (but I'll say it anyway) — if the dishwasher is really running hot as it should, and the washer arms are spinning (all levels), and it is getting dishwasher soap in the correct amounts, by the time it has finished and run its rinse there should be no trace of grease or greasy film on anything.

Now… what bothers me is that that film will also be on all or some of you dishware… yuch.

mattmia2 · May 24

is this a new problem? some dishwashers just are terrible.

zarkbuilder · May 24

UPDATE: Did some cleaning: no change. So, I ran INDIVIDUAL runs of different cleaners. Each empty DW cleaning run was set to heavy cycle, Hi temp, no rinse aid, all possible jets active, no heated dry cycle (open door). Separate runs of: C*sc*d* Platinum Dishwasher Cleaner, Distilled Vinegar (full strength), Lem*Sh*ne, CLR (with a second full rinse only run). No change. I have not used pure citric acid yet, but I know the Lem* product is similar for now. The film is on the stainless steel interior surface, but not on the dishware. Throughout the filter has had almost no debris. I clean the filter every couple of weeks, but for this situation I have been checking after every run. The greasy film is more noticeable after the cleaners are used. I do notice the wiped-off areas do not accumulate new grease. Also, the basement DW (1 year old low end foreign brand) does not accumulate grease or rust. Stainless interior looks like day 1. We clean heavy pots and pans in the downstairs unit. I may try to manually clean the interior of the kitchen DW and see if that 'resets' the environment. Everyone on the forum has been VERY helpful and it is truly appreciated. I will report back.

mattmia2 · May 24

dow athroom cleaner or lysol bathroom cleaner, the kind that comes in a spray can and foams will take the film off if you spray and soak then wipe it off.

maybe something with wax got put in there and melted to the inside of the dishwasher

Rust in Dishwasher?

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