Bosch Dishwasher Service Test Result 2: Heating Group

What 2 means

A 2 from the service test program points to the heating system on an older Bosch dishwasher. Bosch casts the net wide on purpose, naming five parts in a single entry: the heater, overheat thermostat, flow switch, NTC temperature sensor and the heater relay on the control board. They also sit behind the long-cycle display, so water that is slow to warm is the typical story.

Common causes of 2

Through-flow heater dead, or the overheat thermostat open
Flow switch or NTC sensor going bad
Heater relay on the control board burned out

✓ One safe check you can try

1. Let the kitchen hot tap run until it is hot. 2. Start a cycle right after. 3. Cold fill water makes a healthy heating system seem sluggish, because these machines heat what comes in instead of waiting for it. 4. If the problem persists with a hot start, stop and call us.

! Why to stop there

Five parts share one result, so guessing is costly.
Heater circuits run on 120V beside standing water.
A relay problem on the control module is a different repair from a heater.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Dishwasher codes

E:01Bosch Dishwasher E:01: Cycle Ended Early, Heater Relay or Pump Unconfirmed E:30Bosch Dishwasher E:30, Voltage Too High and the Machine Shut Down E:31Water in the Zeolite Container - Bosch Dishwasher E:31 FBosch Dishwasher F on an Older Display (Water Filling) 2HBosch Dishwasher 2H: Long Cycle Warning on Older Displays 1Bosch Dishwasher Service Test Result 1: Aqua Sensor 4Bosch Dishwasher Service Test Result 4: Water Filling 8Bosch Dishwasher Service Test Result 8: Temperature Sensor

22 questions

Why are so many parts listed under one number?

Bosch groups them because they all affect heating. We test each in turn with meter readings to find the one that failed, instead of replacing all five.

Is a cold supply really a cause?

Yes. The machine heats the incoming water, so cold water at the start can stretch a cycle. Running the hot tap first rules that out before any part is touched.

Will it clean at all without heat?

Poorly. Grease does not lift well in cool water, so dishes come out cloudy or greasy. Having the heating checked soon is worth it, since the dishes will keep coming out poorly.