Bosch · Dishwasher

E6

Water Heater Fault

Severity

Medium

When a Bosch Dishwasher shows E6 on its display, the internal diagnostic system has flagged a condition known as "Water Heater Fault". Most repairs for this code are straightforward and can be completed at home.

Owner's Summary

Your Bosch dishwasher is washing with cold water — dishes are coming out with food residue because the sanitizing hot water is not reaching the right temperature. The NTC temperature sensor is the most likely cause and is an affordable fix.

Symptoms

Bosch dishwasher not heating water, dishes come out cold and dirty, E6 displayed

Common Causes

Faulty NTC temperature sensor
Failed flow heater assembly
Burned relay on control board
Wiring issue to heating element

How to Fix

1 Test NTC thermistor resistance — typically 10–30k ohms at room temp
2 Test heating element continuity
3 Inspect wiring harness from PCB to heater
4 Replace NTC sensor if out of spec
5 Replace flow heater assembly if element has no continuity

Tools You'll Need

Multimeter Flashlight

These are simple, low-risk fixes most homeowners can do with tools already in a basic toolbox.

Technical Explanation

The Bosch EGO module regulates wash temperature by cycling the flow heater based on NTC feedback. E6 is triggered when the module detects water temperature has not reached target within maximum heating time, or when NTC resistance is outside valid range.

Is It Safe to Keep Using?

No urgent safety concern but dishes are not being sanitized properly. Fix within a week.

Technician's Pro Tip

If the heating element tests fine and NTC reads within spec, check the PCB relay that controls the heater — it is a common failure on older Bosch dishwashers. Visual inspection for burn marks or corrosion is straightforward.

Related Codes

E1 — Bosch Washing Machine

Water Intake Fault

High

E18 — Bosch Washing Machine

Drain Fault — Water Not Pumping Out

High

E17 — Bosch Washing Machine

Water Intake Too Slow

Medium

Frequently Asked Questions

What does error code E6 mean on a Bosch Dishwasher?

Code E6 on a Bosch Dishwasher indicates "Water Heater Fault." In practice, the most common trigger is faulty NTC temperature sensor. Severity is rated medium, and typical repair costs range from $20 to $300.

Can I fix E6 myself, or do I need a technician?

Many cases of E6 can be resolved without a technician. The first step to try: test NTC thermistor resistance — typically 10–30k ohms at room temp. If that doesn't clear the code, work through the remaining steps in the "How to Fix" section above before assuming a part needs replacing.

Is it safe to keep using my dishwasher with code E6 showing?

No urgent safety concern but dishes are not being sanitized properly. Fix within a week.

How much does it cost to repair E6 on a Bosch Dishwasher?

Repair costs for code E6 typically range from $20 to $300. NTC sensor: $20–$50; Flow heater: $80–$250; Labor: $80–$150. Costs on the low end usually reflect a DIY fix with no parts required, while the high end reflects a part replacement plus professional labor.

Estimated Repair Cost USD

$20 – $300

NTC sensor: $20–$50; Flow heater: $80–$250; Labor: $80–$150