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.