Bosch Dishwasher Error Code E02 — What It Means & How to Fix It

What Does This Error Mean?

Bosch dishwasher error E02 means the control board has detected a fault with the heater relay. The heater relay is the component that controls power to the heating element. If it fails, the dishwasher cannot heat water to the correct temperature and will stop the wash cycle.

Affected Models

Bosch Series 2
Bosch Series 4
Bosch Series 6
Bosch Series 8
Bosch Silence Plus

Common Causes

The heater relay on the control board has burned out or is stuck in the open position
The heating element itself has failed, causing the relay to trip as a safety measure
A wiring connection between the control board and the heating element is loose or broken
A power surge damaged the control board's relay circuitry
The control board (PCB) has a broader fault that is showing up as a relay error

How to Fix It

Turn the dishwasher off at the power switch and unplug it from the wall. Wait 10 minutes, then plug it back in and try running a short cycle to see if the error clears.

Occasionally a relay fault is triggered by a power fluctuation and clears with a full power reset.
If the error returns after a reset, do not keep running the dishwasher. Operating with a faulty heater relay can cause the heating element to run uncontrolled.

The dishwasher will likely not wash effectively without heating, and running it repeatedly can worsen the fault.
Check if the dishwasher is still under warranty. Bosch typically offers a 2-year warranty. Check your purchase receipt and contact Bosch support if within the warranty period.

An E02 error on a relatively new machine is often repaired at no cost under warranty.
Book a qualified appliance repair technician. Describe the E02 error code and the dishwasher model. The technician will test the heating element and inspect the control board.

Provide the model number (found on the door frame sticker) and serial number when booking.
Ask the technician whether the control board or just the relay needs replacement. In some cases only the relay is faulty — a full board replacement is more expensive but may be recommended.

Control boards for Bosch dishwashers typically cost $100 to $250 for the part alone.

When to Call a Professional

E02 is a critical error that almost always requires a qualified appliance technician. Replacing a heater relay involves working inside the dishwasher's electrical system with mains voltage components. Do not attempt this repair yourself unless you are a qualified electrician.

Frequently Asked Questions

Can I still use my Bosch dishwasher with an E02 error?

Technically the dishwasher may still attempt to run, but it will not heat water properly. Dishes will not be sanitized and may not come out clean. It is best to stop using it until the relay is repaired.

Is E02 covered by Bosch's warranty?

If your dishwasher is within its warranty period (typically 2 years), yes — E02 should be covered as a manufacturing defect. Contact Bosch customer service with your model number and proof of purchase. They will arrange a repair or replacement.

What is a heater relay and why does it matter?

A relay is essentially an electrically operated switch on the control board. The heater relay controls when the heating element turns on and off during the wash cycle. If it fails open, the heating element never gets power — if it fails closed, the element never turns off, which is a fire risk.