Thermador error codes are separated into four severity levels. According to Thermador’s support documentation, 60% of homeowner-reported errors resolve through filter cleaning and drain system inspection. The remaining 40% require factory-certified diagnosis of heating elements, control boards, or sealed pump assemblies.
CRITICAL: Immediate Action Required
E15 – Water Leak Detected
Safety shutoff triggered—water present in base pan. Continued operation risks include electrical short, cabinet damage, and flooring destruction.
Immediate steps: Turn off the water supply, disconnect power, and check for standing water under the unit. Do not restart until professionally inspected. Common causes include failed door seals, cracked inlet hoses, or a leak from the pump assembly.
E27 – Low Voltage Supply
The electrical system is providing insufficient power. This indicates a household electrical problem, not a dishwasher defect. Contact a licensed electrician before operating—inadequate voltage damages control boards.
URGENT: Service Needed Within 48 Hours
E01/E04/E0105 – Heating System Failure
Heating element or relay malfunction. Dishes won’t dry properly, and sanitization cycles fail. Power reset (30 seconds at the breaker) resolves 20% of cases—if error returns.
Restaurant kitchens and homes requiring sanitization cycles need immediate service—health department compliance depends on proper heating function.
E0100-E0110 – Control Board Faults
Electronic failures in the main control board, relay circuits, or motor communications. These don’t resolve through homeowner intervention. Control board replacement runs $400-$600, requires programming to the unit’s serial number.
MODERATE: DIY Resolution Possible
E22 – Filter Blocked
Most common homeowner-fixable error. Remove filter at dishwasher bottom, clean under running water with soft brush and mild soap. Reinstall completely dry.
Prevention: Clean filter every 2 weeks in hard water areas, monthly otherwise. Highland Village and Memorial residents with hard water should use softener salt—limescale accelerates filter clogging.
E24 – Drainage Issue
The dishwasher cannot drain properly. Thermador-Bosch documentation identifies three main causes:
- Clogged drain pump (40% of E24 errors): Remove pump cover at bottom left, clear debris, ensure cover clicks firmly into place
- Kinked drain hose (30% of E24 errors): Check the hose run from the dishwasher to the disposal/sink drain for sharp bends
- Garbage disposal plug not removed (20% of E24 errors): New disposals have a knockout plug in the dishwasher connection—must be removed
If recently installed garbage disposal, check the disposal’s dishwasher inlet for a plug before calling service.
E25 – Drain Pump Blocked or Cover Loose
Similar to E24 but specifically indicates pump impeller obstruction or loose pump cover. Remove pump cover (single Torx screw), clear impeller area, verify cover clicks into locked position.
Glass fragments, toothpicks, and twist-ties commonly jam pump impellers. Miele and KitchenAid dishwashers experience identical issues.
E18 – Low Water/Fill Issue
Insufficient water entering the dishwasher. Verify water supply valve is fully open (under sink), check inlet hose for kinks. Thermador troubleshooting recommends running 2 gallons through the supply line to clear airlocks.
If the supply line is clear and the valve is open, the problem lies in the inlet valve assembly or the pressure sensor.
MAINTENANCE: Preventive Action
E12 – Limescale Buildup
Heat pump contains mineral deposits affecting water flow and heating efficiency. Use commercial descaler (Bosch/Thermador brand recommended): empty dishwasher, add descaler to detergent compartment, run hottest/longest cycle, follow with rinse-only cycle.
Dallas and Houston’s hard water accelerates limescale formation. Homeowners without water softeners should descale quarterly, versus annuall for softened water systems.
Prevention: Use dishwasher salt in units equipped with a water softener function. This prevents limescale formation rather than removing existing buildup.
Your Next Steps Based on Error Code
Seeing E15 or E27? Stop immediately. Disconnect power/water. Call (214) 761-8300 Dallas or (281) 758-9978 Houston for emergency service. Risk of damage increases hourly.
Seeing E01, E04, E0105, or E0100-E0110? Power reset at the breaker (30 seconds). If an error returns, schedule service within 48 hours. The unit remains functional for basic washing but lacks proper sanitization.
Seeing E22, E24, E25, or E18? Attempt DIY resolution using severity-based guidance above. If the error persists after cleaning the filter, checking the drain system, and verifying the water supply, schedule diagnostic service—these errors indicate failed pumps, valves, or sensors requiring factory-certified repair.
Seeing E12? Purchase descaling solution, follow the maintenance procedure. If the error persists after descaling, the heating element requires professional inspection—limescale may have caused permanent damage.
Factory-certified Thermador service ensures proper diagnosis, genuine OEM parts, and 2-year warranty coverage. Generic repair services misdiagnose control board issues as pump failures, leading to $200-$400 unnecessary repairs before identifying the actual problem.
Need expert diagnosis? Call (214) 761-8300 for Dallas or (281) 758-9978 for Houston.
