Miele Dishwasher F13 Error Code: Salt System Fault
Quick Answer
Miele F13 is a salt system fault. In the majority of cases it is simply an empty salt container or an improperly closed salt cap. Open the salt container (inside the wash cabinet floor, on the left side), check the level, and top up with dishwasher regenerating salt if needed.
If you ignore F13, you're basically washing your dishes in hard water and you won't notice until your glasses look sandblasted. Honestly, nine times out of ten when I get called out for this it's just empty salt or a cap that wasn't tightened. The other times it's a conductivity sensor caked in scale. Either way, start with the cheap fix first because it's almost always that.
MieleDishwasherSeverity: low95% DIY Success
Time to Fix
3–15 min
Difficulty
beginner
Parts Cost
$8 – $18
Tools Needed
Funnel, wide-mouth (Miele includes one, any wide-mouth funnel also works), Flashlight (for inspecting the conductivity sensor contacts)
What Does the F13 Code Mean?
OK so Miele dishwashers have a built-in water softener, which is genuinely great if you're in a hard water area. That softener runs on coarse regenerating salt. Not table salt. Not pool salt. The machine watches the salt concentration through a small sensor, and when that sensor reads low, you get F13. Usually costs nothing to fix. Usually. I've seen this code cleared in two minutes with a bag of salt from the grocery store.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Salt container empty or nearly depleted40%
Salt container cap not fully tightened (loses seal, dilutes too fast)24%
Wrong type of salt used (table salt or pool salt)14%
Conductivity sensor failure12%
Conductivity sensor coated with salt bridge or scale10%
Symptoms You May Notice
F13 code on the display, sometimes steady, sometimes flashing depending on your model
The dedicated salt indicator light is lit up separate from the fault code on some models, check your panel
Glasses coming out with a white cloudy film that doesn't wipe off, like they've been frosted over from the inside
Machine keeps throwing F13 even an hour after you just filled the container
Dishes feel gritty or have a faint mineral smell after a cycle
Can you reset a Miele dishwasher to clear the F13 code?
Fill the salt container all the way to the top and tighten the cap firmly until it won't turn anymore. Start a Rinse cycle or the shortest wash program on your machine. Don't open the door mid-cycle. When it finishes, check the display. F13 should be gone. If it's not, run one more rinse before you panic, because sometimes the sensor needs two full flushes to read the new brine concentration correctly.
Tools Required for Diagnosis
Funnel, wide-mouth (Miele includes one, any wide-mouth funnel also works)Flashlight (for inspecting the conductivity sensor contacts)Long wooden spoon or dowel rod (to break up a salt bridge if needed)Clean rag or paper towels (wipe up spilled salt from the tub floor immediately)White vinegar (for dissolving scale off the conductivity sensor contacts)Phillips #2 screwdriver (only needed if replacing the conductivity sensor)
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
Replacement Parts
If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.
Part Name
OEM Number
Estimated Price
Salt Container Cap with Seal6819390 · $8–$18
6819390
$8 – $18
Frequently Asked Questions
What type of salt do I use for my Miele dishwasher?
Coarse dishwasher regenerating salt, that's it. Finish, Somat, or whatever your supermarket sells as dishwasher salt all work fine. What you absolutely can't use is table salt, iodized salt, pool salt, water softener pellets, or those Himalayan pink salt things your neighbor swears by. Table salt is especially bad because the additives foul the ion exchange resin inside the softener over time and that's an expensive fix. Grab a 4-lb bag of Finish dishwasher salt at the grocery store and you're sorted.
Does Miele F13 affect wash quality right away?
Not immediately, but give it a few weeks and you'll notice. Your glasses will start coming out with a white haze or film that doesn't wipe off. That's limescale, basically hard water minerals depositing because the softener isn't doing its job anymore. Glasses show it first because they're clear and you notice it. Run it long enough without salt and you'll get scale on the heating element too, which makes the machine less efficient and eventually shortens its life. Top up the salt and you'll never deal with any of this.
My Miele dishwasher shows F13 right after I refilled the salt. Why?
Almost definitely the cap seal. If F13 comes back within one or two cycles of a fresh refill, fresh water from the wash is getting into the reservoir and constantly diluting your brine, so the sensor never reads a proper concentration no matter how much salt you put in. Pull the cap off, check the rubber O-ring on the underside, dry off the seating surface, make sure the O-ring is seated evenly in its groove, and retighten firmly. If the O-ring is cracked or flat, a replacement cap is about $10 and fixes it completely.
How often do I need to add salt to my Miele dishwasher?
Honestly it depends on your water hardness and how much you run the machine. In a hard water area with daily use, I've seen households burn through a full bag every 3-4 weeks. Softer water, you might go 2-3 months between fills. Your machine has a water hardness setting in the menu, and dialing that in to match your actual water hardness will help it use salt more efficiently. Most Miele machines also show a salt indicator light before you hit F13, so if you catch that early you'll never see the fault code at all.
Can I keep running the dishwasher while F13 is showing?
Technically yes, it'll still wash your dishes. But you're running on unsoftened water and slowly building limescale on everything inside the machine. Short term, a few cycles isn't going to kill anything, like if you're out of salt and waiting for a delivery that's fine. Just don't let it run for weeks on end without salt because eventually you'll get scale buildup on the heating element that's a real pain to deal with. Salt costs maybe $5 a bag. Just grab it at the store.
What is a salt bridge and how do I fix it?
A salt bridge is a hard crusty arch that forms at the top of the salt reservoir, kind of like a dome over the water below. It looks full when you peer down in there, but there's empty space or plain water underneath, so no salt is actually dissolving into the brine. Happens when the machine sits unused for a while or in humid environments. Fix it by poking through the crust with a long wooden spoon or a dowel rod. Break it up and let it drop to the bottom. Run a rinse cycle and F13 should clear once the salt dissolves properly.