Error code reference

Bosch Dishwasher Error Code E1

Heating error

Bosch codesBosch dishwasher codes

Heating error – the dishwasher has detected a problem with the heating system.

First step from the service manual

Check heater resistance (~11 ohms), flow switch (~0.4 ohms), NTC (~55K ohms at 72°F), Hi-Limit (~0.3 ohms), control heater relay and solder joints, and wire harness/terminals.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What E1 means on a Bosch dishwasher

The E1 error code on a Bosch dishwasher indicates the control board detected a heating failure during the wash or dry cycle. The board monitors water temperature through the NTC thermistor and expects the heater element to raise water temperature within a defined time window. When that threshold is not reached, E1 is triggered. The fault can originate from the heating element itself, the flow switch that confirms water circulation over the heater, the NTC thermistor, the hi-limit thermostat, or a failed heater relay on the control module.

For a homeowner, this means your dishwasher is not heating the water properly, which affects both cleaning performance and sanitization. The machine shuts down to prevent potential damage from running a dry heater. The most common culprits are a burned-out heating element or a faulty NTC sensor, both of which are accessible parts. Before assuming the worst, check that water is actually filling to the correct level, since the heater requires submersion to function safely. A failed hi-limit thermostat or degraded wiring harness connection can also produce this code without the heater itself being at fault.

Source: manufacturer service documentation.

Common causes of E1

  1. 01

    Failed heating element

    Part replacement

    The heating element should measure approximately 11 ohms across its terminals. A burned-out or open-circuit element will read OL (infinite resistance), preventing any water heating and triggering E1.

  2. 02

    Faulty NTC thermistor

    Part replacement

    The NTC thermistor reports water temperature to the control board and should read approximately 55k ohms at 72°F. A drifted or open NTC causes the board to see incorrect temperatures and may trigger E1 even if the heater itself is functional.

  3. 03

    Tripped or failed hi-limit thermostat

    Part replacement

    The hi-limit thermostat protects the heater from overheating and should measure approximately 0.3 ohms when closed. If it has opened due to an overheat event or internal failure, the heater circuit is broken and E1 will appear.

  4. 04

    Defective flow switch or wiring harness fault

    Wiring / connection

    The flow switch confirms water is moving across the heater and should read approximately 0.4 ohms when activated. A failed flow switch, corroded terminal, or damaged wire in the heater circuit harness can interrupt the signal and cause the control board to log E1 without the heater element being defective.

See the test procedure for each cause

Frequently asked questions about E1

What does E1 mean on a Bosch dishwasher?
E1 on a Bosch dishwasher means the control board detected a heating error. The dishwasher monitors water temperature using the NTC thermistor and expects the heating element to raise water to a target temperature within a set time. When that does not happen, E1 is logged and the cycle is halted. The fault can involve the heating element, NTC thermistor, hi-limit thermostat, flow switch, or the heater relay on the control board.
How do I fix E1 on a Bosch dishwasher?
Start by unplugging the dishwasher and using a multimeter to test the key components in the heater circuit. Check the heating element for approximately 11 ohms, the flow switch for approximately 0.4 ohms, the NTC thermistor for approximately 55k ohms at room temperature, and the hi-limit thermostat for approximately 0.3 ohms. Also inspect the wire harness for burned or corroded terminals. Replace whichever component reads out of specification. If all components test correctly, inspect the heater relay and solder joints on the control board, which may require board replacement or professional reflow.
Can I still use my Bosch dishwasher when it shows E1?
You should not continue running the dishwasher with an active E1 code. The machine has stopped the cycle specifically because the heating system is not working correctly. Running cycles without proper water heating will result in poor cleaning and failed sanitization. More importantly, if the flow switch or hi-limit is the cause, there is a risk the heater could run without adequate water contact, which can cause additional component damage. Address the fault before resuming normal use.
How much does it cost to fix a Bosch dishwasher E1 error?
Cost depends on which component has failed. A replacement heating element typically runs $40 to $90 for the part. An NTC thermistor or hi-limit thermostat is usually $15 to $40. A flow switch is in a similar range. If the control board's heater relay has failed and the board needs replacement, expect $100 to $250 for the part. Adding professional labor typically brings the total repair to $150 to $400 depending on your area and the part involved. Testing components yourself with a multimeter before ordering parts avoids unnecessary spending.
Can a bad NTC sensor cause E1 on a Bosch dishwasher?
Yes, a faulty NTC thermistor is a genuine and relatively common cause of E1. The NTC reports water temperature to the control board throughout the cycle. If it has drifted out of its correct resistance range or has failed open, the board either sees an implausible temperature reading or loses the signal entirely and triggers E1. At 72°F the NTC should read approximately 55k ohms. A reading significantly above or below this, or an open circuit reading, confirms the NTC needs replacement.

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