Bosch Dishwasher Error Code #H

#H on a Bosch Apexx display dishwasher indicates a heating system fault. The control board has detected a problem somewhere in the heating circuit, which includes the heating element, the hi-limit thermostat, the flow switch, the NTC temperature sensor, or the heater relay on the control module. The code does not identify which component specifically has failed, so some diagnostic testing is required.

Start by checking the NTC sensor with a multimeter for correct resistance at room temperature (typically around 10k ohms for Bosch NTC sensors, but verify against your model's service data). Then test the hi-limit thermostat for continuity and the heating element for continuity and correct resistance. Inspect the flow switch for mechanical function and electrical continuity. If all those components test good, the heater relay on the control module is the likely culprit and the module will need replacement. Each failed component requires a part replacement.

A reset may temporarily clear the #H code, but it will return as soon as the control board runs its heating circuit checks again during the next wash cycle. A reset does not fix the underlying component failure. Use the reset only as a way to confirm the code is reproducible, not as a repair.

Running the dishwasher with an active #H code is not recommended. Without a functioning heating system, the machine cannot reach the temperatures required to sanitize dishes or activate dishwasher detergent effectively. More critically, if the hi-limit or flow switch has failed in a way that leaves the heater energized without proper water flow, continuing to run the machine could damage internal components or create a safety hazard. Stop using the machine until the fault is diagnosed.

Repair cost depends entirely on which component has failed. An NTC sensor is typically the least expensive fix, with parts running $15 to $40 and minimal labor if you are comfortable with basic appliance disassembly. A heating element replacement runs $50 to $100 in parts. A hi-limit thermostat is inexpensive at $10 to $30. If the control module has a failed heater relay, module replacement is the most expensive outcome, often $150 to $300 in parts alone, making professional diagnosis worthwhile before committing to that repair.