Bosch · Dishwasher · Heating Problem

Bosch Dishwasher Error E03

Bosch dishwasher error E03 usually indicates a heating-system fault. ECL records this code as “Auxiliary Heating Error”. Common causes on this page include Heater fault and Thermostat issue, but the exact cause can vary by model and appliance generation. Keep to the external checks and safety guidance below; do not remove covers or test internal or live components, and arrange professional diagnosis if the code persists.

Quick answer: Auxiliary Heating Error

In simple terms

Bosch dishwasher code E03 usually means Auxiliary Heating Error. Follow these four steps.

1Understand the code

See what the code usually means and why it may have appeared.

2Try safe checks

Try only the simple checks listed on this page. Do not take the appliance apart.

3Check if it is safe to use

Check the safety section before you keep using the appliance.

4Choose the next step

Use the next-step box to see whether to keep checking, find a part by model or get repair help.

What Bosch E03 means

The auxiliary heating system is not operating within range.

Repair help

Need help with E03?

This fault may need proper testing with tools. If you have followed the safety guidance above, ECL can pass the fault details to a checked repairer who covers your area.

Find an ECL Verified repairer

No obligation. Your contact details are only shared after you submit the repair request, and only with a suitable ECL Verified repairer where coverage is available.

Common causes

  • Heater fault
  • Thermostat issue
  • Control board fault

Safe checks you can make

  1. Run a reset cycle

When to stop and call an engineer

If standard user maintenance does not clear the error, or if you suspect an electrical component failure.

Your model may be different

Error-code meanings can vary by model, market and appliance generation. Confirm Bosch E03 against the instruction manual or support information for the exact model number before replacing parts or treating this page as a model-specific diagnosis.

Where this information comes from

Publisher: Error Code Lookup Editorial Team. This page is independent information written in our own words and reviewed with safety boundaries in mind.

Manufacturer information: Bosch UK User Manuals. Use the exact model number to verify model-specific wording and instructions.

Last reviewed: 2026-05-18

How Error Code Lookup researches and verifies pages · Report a correction or provide model-specific evidence

Frequently asked questions

What does E03 mean on a Bosch dishwasher?

The auxiliary heating system is not operating within range.

What usually causes Bosch error E03?

Common causes include Heater fault; Thermostat issue; Control board fault.

Can I safely fix E03 myself?

This fault may require professional diagnosis or repair. Only basic external safety checks should be attempted.

When should I call a professional for E03?

If standard user maintenance does not clear the error, or if you suspect an electrical component failure.

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