The Miele F78 error indicates a circulation pump fault, meaning the main wash pump cannot pressurize water. The most common fix is clearing debris like glass or seeds from the pump impeller located beneath the filter assembly.
Here's what usually happens: the machine fills, the wash phase starts, you hear one loud hum, then silence. F78. If you keep hitting Start trying to power through it, you're cooking the motor against a blockage that might've been a free fix. I'd say 7 out of 10 of these calls are debris, not a dead pump. But when it is a dead pump on a Miele, it's not cheap. Don't ignore it.
OK so F78 means the pump that pressurizes water to your spray arms is either jammed or dead. Miele's pump is a sealed unit, motor and impeller together, so you can't replace just one part. Good news is most of the time it's debris, not a dead motor. I've pulled wine glass shards, cherry pits, olive stones, even a zip tie from these sumps. Check for blockage first before you spend money on anything.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Foreign object (glass shard, seed, bone fragment) blocking impeller40%
Circulation pump motor winding failure24%
Wiring harness fault on pump connector22%
Capacitor failure on pump motor14%
Symptoms You May Notice
Cycle stops dead during the wash phase with F78 on the display and a full drum of water that never got circulated to the spray arms.
You can hear the machine fill up completely normally, but when the wash phase should kick in, there's either silence or a single loud hum that lasts a few seconds and then cuts out.
Dishes coming out with dried food still on them and spray arms that aren't moving when you open the door mid-cycle.
Sometimes you catch it early as a grinding or rattling sound during the wash phase, then F78 shows up either that cycle or the next one.
Can you reset a Miele dishwasher to clear the F78 code?
After clearing debris or replacing the pump, press and hold Start/Stop for about 3 seconds to cancel the fault state. Wait 30 seconds, then start a short program like Quick Wash or Rinse Only. F78 clears automatically once the pump runs successfully. If the code comes right back within the first few minutes, there's either more debris in the sump or the motor's actually failed and needs replacement.
Tools Required for Diagnosis
Phillips #2 screwdriverNeedle-nose pliersLong flathead screwdriverMultimeter with ohms settingFlashlight or headlampShallow pan or towels to catch water from sump
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
ComponentComponent Under Test
Expected Range80–150 ohms
ConditionIf Open (OL) or infinite, replace component.
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.
F78 is the circulation pump fault. The circulation pump is the main one that pushes water through the spray arms during wash and rinse, not the drain pump. When F78 fires, the control board detected the pump motor drawing abnormal current. Either too much because something's jamming the impeller, or too little because the winding's gone. Start with the debris check through the filter sump before assuming it's a dead motor. Honestly, 6 or 7 out of every 10 F78 calls I go out on are just a piece of glass or a pit that got through the filter.
How much does a Miele circulation pump replacement cost?
The pump assembly runs $90-165 depending on your specific G series model. Labor from a Miele authorized tech adds $150-250 on top of that, so you're looking at $250-400 all-in for a professional repair. If you're comfortable pulling the dishwasher out and getting into the sump area, it's doable as a DIY job in about 60-90 minutes. Make sure you get the right pump for your exact model number because Miele uses different pump assemblies across the G series.
Can I run my dishwasher while F78 is showing?
No, don't try it. The machine won't actually wash anything because the circulation pump is either jammed or dead, so you'd just be wasting water and power. Worse, if the pump's jammed against debris and you force a cycle, you risk burning out the motor windings permanently. That turns a free fix, literally just pulling out a piece of glass, into a $150 parts bill. Just don't run it until you've cleared the fault.
How do I access the impeller on a Miele dishwasher?
It's actually more accessible than a lot of other brands. Pull both racks out, remove the lower spray arm by twisting the center nut counterclockwise, then remove the triple filter. The round coarse filter twists out first, then the flat fine filter pulls straight up. Once those are out you can see down into the sump where the impeller sits. Flashlight helps a lot here. Use needle-nose pliers to fish out anything that doesn't belong, and test that the impeller spins when you poke it. Takes about 5 minutes to get to this point.
F78 came back right after I cleared the blockage. Now what?
OK so if you pulled something out, ran a cycle, and the code came back fast, one of two things is happening. Either there's more debris still in there that you missed the first time, so do the inspection again really carefully with a good light. Or the blockage already damaged the motor before you caught it. Do the motor resistance test with your multimeter. If you get OL instead of 80-150 ohms, the winding's gone and the pump took too much heat running jammed. You'll need a new pump assembly at that point, no way around it.
Is F78 covered under Miele's warranty?
If your machine's under the standard 1-year warranty, yes, a failed pump motor should be covered. But a blockage from foreign debris like glass or a cherry pit usually isn't, because that's considered misuse or lack of pre-rinsing. Miele also sells extended warranties, and if you bought one, call them first before you do anything yourself. A service call on a valid warranty is free, and Miele techs can usually get out pretty quickly in most metro areas.