How do I fix Bosch Dishwasher Sump Seal Replacement - Signs & How-To?

Follow the step-by-step diagnosis below. The most likely fix is identified by checking power, sensor resistance, and control-board signals in order — using a multimeter and the part numbers documented in the parts reference table.

Can I keep running the equipment with this fault active?

Generally no. Faults on Appliance units are emitted when a sensor, safety, or control circuit is outside its operating envelope. Running through an active fault risks compressor, heater, or control-board damage. Diagnose and clear the fault first.

What part is most commonly replaced for Bosch Dishwasher Sump Seal Replacement - Signs & How-To?

The most frequently replaced parts for Bosch Dishwasher Sump Seal Replacement - Signs & How-To are listed in the Parts Reference section of this guide with OEM part numbers and typical price ranges. Check the table for direct replacements.

Is Bosch Dishwasher Sump Seal Replacement - Signs & How-To a DIY repair or do I need a technician?

Sensor swaps, fan motor replacements, and condenser cleaning are typical DIY-level repairs. Anything involving refrigerant, gas, or high-voltage (>240V) work requires a licensed technician for both safety and code-compliance reasons.

Bosch Dishwasher Sump Seal Replacement - Signs & How-To

Q: What does Bosch Dishwasher Sump Seal Replacement - Signs & How-To mean?

E15 error, water in base pan, flood switch triggered, dishwasher won't run. Replacing the sump seal and O-ring stops the leak and clears the code.

Bosch Dishwasher Sump Seal Replacement — What This Part Does

The sump assembly sits at the bottom of the dishwasher tub and collects water before the pump sends it through the spray arms or drain. A large O-ring seal sits between the sump housing and the tub to keep water inside the wash chamber. Over time this seal can harden, shift out of position, or get pinched during reassembly, allowing water to seep past the joint and drip into the base pan below.

When enough water collects in the base pan, Bosch’s flood protection switch activates and triggers the E15 fault code. The dishwasher locks out to prevent further leaking. A displaced or damaged sump seal is the most common cause of E15 in the field. Replacing the seal kit with the correct Bosch parts and reseating the sump properly stops the leak and clears the error.

Jump to Replacement Steps

Signs It Needs Replacing

E15 error code displayed The dishwasher shows E15 on the control panel and will not start a cycle because the flood protection system has been triggered.
Water pooled in the base pan under the dishwasher You tip the unit back or remove the kick plate and see standing water in the plastic base tray below the tub.
Dishwasher won’t reset after clearing water Even after mopping out the base pan, the E15 returns within one or two cycles because the sump seal is still leaking.
Visible seepage around the sump-to-tub joint Water drips or seeps from the area where the sump assembly bolts to the bottom of the tub during a wash cycle.
Seal looks flattened, cracked, or out of position When you remove the sump, the O-ring is visibly damaged, pinched, or not seated evenly in its groove.
E15 appeared after a previous sump repair The code started shortly after you or another tech removed and reinstalled the sump, suggesting the seal was not positioned correctly.

How to Replace It

Unplug the dishwasher and shut off the water supply valve under the sink or at the wall.
Remove the lower dish rack and unscrew the spray arm and any filters or covers to expose the sump area in the bottom of the tub.
Tip the dishwasher back or remove the front kick plate and use towels or a shop vac to extract all standing water from the base pan.
Disconnect the wire connectors and hose clamps on the sump assembly, then remove the screws or fasteners securing the sump to the underside of the tub.
Lower the sump out of the tub and peel off the old O-ring seal from both the sump flange and the tub surface, cleaning any residue or debris from the sealing surfaces.
Use the wire installation tool included in the Bosch repair kit to stretch the new O-ring into the groove on the sump flange, working your way around the entire perimeter so the seal sits evenly without twists or pinches.
Lift the sump back into position against the tub, align all bolt holes, and install the new screws from the repair kit, tightening them in a cross pattern to seat the seal evenly all the way around.
Reconnect all hoses and wire connectors, then run a short rinse cycle while watching the sump joint and base pan for any signs of leakage.
If the joint stays dry and the E15 does not return, reinstall the spray arm, filters, and kick plate, then restore power and water and return the dishwasher to service.

The Part You Need

Part	Notes
Bosch sump seal repair kit (12005744 or 12026667)	Amazon \| Kit includes new O-ring seal, screws, and installation wire tool. Check your dishwasher’s model and serial number on the door-edge or side-wall label to confirm fit. Part 12005744 includes the tool and instructions; 12026667 is seal and screws only.

If this part is failing you may also see one of these codes:

When to Call a Pro

If you are not comfortable tilting the dishwasher to access the base pan, disconnecting multiple hoses and electrical connectors under the tub, or using the wire tool to seat the new O-ring without twisting it, call an appliance technician. If the E15 returns after you replace the seal and verify correct installation, the leak may be coming from a cracked sump housing, a different hose joint, or another source above the base pan, and a pro with pressure-test equipment can pinpoint the fault. Any crack in the sump itself usually means replacing the entire pump-and-sump assembly rather than just the seal.