Thermador Dishwasher Error Code E15 — Water in Base / Leak Protection Activated
What this means
Error E15 on Thermador dishwashers (built on the BSH/Bosch platform) indicates the AquaStop leak protection system has been activated. A float switch in the base pan has risen, signaling that water has leaked from a hose, connection, or internal component into the bottom of the unit. The dishwasher immediately stops all water intake and activates the drain pump to remove as much water as possible. This is one of the most common Thermador dishwasher errors and can be caused by a leaking door seal, cracked spray arm, loose hose clamp, faulty aquastop valve, or condensation buildup.
Alternate codes: E:15
Step-by-step fix
4 stepsDrain any standing water and tilt the unit
Turn off the dishwasher and disconnect it from power. Turn off the water supply valve. Place towels around the base. Carefully tilt the dishwasher forward about 30–45 degrees to allow water in the base pan to drain out through the front (have a shallow pan or towels ready). Hold for 30 seconds, then set it back level.
Tilting the dishwasher resets the float switch. On Thermador models, the E15 will not clear until the float switch drops back down, and tilting is the fastest way.
Inspect for the leak source
Remove the dishwasher from the cabinet if possible (or pull it forward). Remove the side panels or base cover plate. Use a flashlight to inspect all hose connections, the door gasket, the sump assembly, and the spray arm connections for signs of water trails, drips, or corrosion. Tighten any loose clamps.
Run a short cycle while the panels are off and watch for the leak location — this is the most reliable way to find where the water is coming from.
Check the door gasket
Inspect the rubber gasket around the dishwasher door opening. Look for tears, hardening, deformation, or food debris preventing a proper seal. Clean the gasket with warm soapy water and check that it seats evenly when the door closes.
Thermador dishwasher door gaskets should be replaced every 5–7 years. A gasket that has hardened will no longer seal properly.
Check the AquaStop valve
The AquaStop valve is located at the end of the water supply hose where it connects to the tap. If the valve has been triggered, it may need to be reset or replaced. Check for visible damage or water marks on the valve body. Some models have a one-time trigger that requires a new AquaStop hose if activated.
Thermador uses the same BSH AquaStop system as Bosch — Bosch replacement parts are fully compatible.
When to call a professional
If you cannot identify the leak source, or if the leak is from the sump assembly or internal plumbing, a Thermador authorized technician should perform the repair. Ongoing E15 errors can indicate a cracked tub or failed internal component.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
Learn more about our sourcesParts you may need
AquaStop Inlet Hose with Valve
Part #00667327 · $50–$100
If AquaStop valve has been triggered or is leaking
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