Bosch Factory Service ManualFault Code: E20

Bosch Washer Error Code E20: Water Heating Circuit / NTC Sensor Discrepancy

The wash control board detects an unexpected temperature sensor reading or zero temperature rise during an active wash heating cycle.

Target Appliance

washer

OEM Certified Technical Diagnostic Tree

Diagnostic Tool Required

Digital Multimeter

Measure Ohms resistance, continuity & line voltage.

Triage Complexity

Advanced Diagnostic

4 Sequential manufacturer inspection branches.

Sequential Factory Diagnostic Tree

Perform each diagnostic step in order. Disconnect electrical power and turn off utility shutoffs before inspecting wiring or internal mechanical assemblies.

Step 1: Physical & Electrical InspectionMultimeter & Visual

Action: Disconnect power, remove front lower service access panel or rear tub cover to locate the tubular heating element.

Bench Test: Disconnect heater power leads and measure resistance across the two element terminals.

Expected Standard: 24 to 30 ohms resistance at room temperature on 120V/240V models.

If Failed / Out of Spec:

Heating element open (0L). Replace tubular wash heating element (00649359).

If Passed:

Proceed to Step 2.

Step 2: Physical & Electrical InspectionMultimeter & Visual

Action: Test resistance across the NTC temperature sensor inserted into the heating element rubber bracket.

Bench Test: Measure resistance across NTC pins at 68°F and 86°F.

Expected Standard: Approximately 5,000 to 6,000 ohms (5k–6k Ω) at 68°F, decreasing as water warms.

If Failed / Out of Spec:

NTC sensor open, shorted, or drifted. Replace NTC temperature sensor (00605156).

If Passed:

Proceed to Step 3.

Step 3: Physical & Electrical InspectionMultimeter & Visual

Action: Inspect wiring harness from heating element and NTC sensor up to main control board.

Bench Test: Perform continuity check and inspect for wire abrasion where harness routes past tub frame.

Expected Standard: 0 ohms continuity; zero rubbed or pinched wires.

If Failed / Out of Spec:

Repair harness wiring with heat-shrink insulated splices.

If Passed:

Proceed to Step 4.

Step 4: Physical & Electrical InspectionMultimeter & Visual

Action: Inspect heater relay on the main electronic control module.

Bench Test: Check relay solder joints for scorching or broken solder pads.

Expected Standard: Clean PCB board traces with zero heat discoloration.

If Failed / Out of Spec:

Replace main electronic control module (11018241).

If Passed:

Run diagnostic calibration cycle.

Verified OEM Replacement Parts

Cross-referenced factory part numbers for Bosch washer error code E20. Always replace defective components with authentic OEM parts to maintain UL safety certification.

Component Name	OEM Part Number	Manufacturer	Status
Wash Tubular Heating Element with Gasket	`00649359`	Bosch	Direct Fit OEM
Tub Temperature NTC Sensor	`00605156`	Bosch	Direct Fit OEM
Main Electronic Control Module	`11018241`	Bosch	Direct Fit OEM

Need Local Diagnostic Assistance?

Connect with a Certified Bosch Technician in Your Area

If multimeter testing reveals an internal short, locked motor, or fried control board, let an experienced local technician complete the repair with certified OEM replacement parts.

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Frequently Asked Questions: Bosch E20

What causes Bosch washer error code E20?

The wash control board detects an unexpected temperature sensor reading or zero temperature rise during an active wash heating cycle.

Can I reset the E20 code by unplugging the washer?

While disconnecting power for 5 minutes may temporarily clear the display control memory, the E20 code will reoccur once the microcontroller detects the mechanical or electrical fault again.

What OEM replacement parts are required for Bosch E20?

Common OEM replacement components include: Wash Tubular Heating Element with Gasket (OEM #00649359), Tub Temperature NTC Sensor (OEM #00605156), Main Electronic Control Module (OEM #11018241).