Bosch SMS40C02GB Heating Troubleshooting

Diagnostic Guide & Solutions

Dishwasher Heating System

Common Heating Issues

Typical Heating Problems:

  • Dishes not drying properly
  • Water not heating during cycle
  • Longer than usual cycle times
  • Error codes related to heating system
  • Inconsistent water temperature

Initial Quick Checks

  1. Check Water Temperature: Ensure incoming water is at least 60°C for optimal performance.
  2. Verify Settings: Confirm Eco or Intensive programs are selected for heating.
  3. Inspect Loading: Ensure dishes are loaded correctly to allow proper water circulation.
  4. Check Detergent: Use recommended dishwasher detergent in proper quantity.
  5. Verify Power Supply: Ensure dishwasher is properly connected to power source.
  6. Rinse Aid Check: Confirm rinse aid dispenser is filled for better drying results.
  7. Filter Inspection: Clean filters to ensure proper water flow and heating.
Warning: Always disconnect power before performing any internal inspections. Heating elements can cause severe burns even when not visibly hot.

Diagnostic Steps

Model Series SMS40C02GB
Heating Element Type Stainless Steel Tubular Heater
Power Rating 2100W
Voltage Requirements 220-240V, 50Hz
Operating Temperature 45-70°C
Heating Element Resistance 22-26 ohms (cold)
Thermostat Cut-out 85°C
Heating Time 8-15 minutes to reach 65°C

Step-by-Step Diagnosis

  1. Visual Inspection: Check heating element for visible damage, burns, or corrosion
  2. Continuity Test: Use multimeter to test heating element continuity (should show 22-26 ohms)
  3. Thermostat Check: Test thermal cut-out and temperature sensors for proper operation
  4. Control Board Test: Verify control board is sending proper voltage to heating circuit
  5. Water Level Check: Ensure proper water level for heating element immersion
  6. Wiring Inspection: Check all connections to heating element and thermal sensors

Heating Error Codes

Error Code Description Solution
E09 Heating system fault - temperature not rising Check heating element, thermostat, temperature sensor
E15 Overheating protection activated Check thermostat, cooling system, water circulation
E22 NTC temperature sensor fault Replace temperature sensor, check wiring
E24 Heating time exceeded Check heating element, water inlet temperature
E25 Heating circuit short circuit Check heating element for short, replace if necessary
E26 Heating circuit open circuit Check heating element continuity, replace if broken

Temperature Sensor Specifications

  • Type: NTC Thermistor
  • Resistance at 25°C: 10k ohms
  • Temperature Range: 0-100°C
  • Accuracy: ±1°C
  • Location: Bottom of tub near heating element

Heating Components

Heating Element

2100W stainless steel tubular heating element located at the bottom of the wash tub. Responsible for heating water during wash cycles and aiding in drying process.

Temperature Sensor

NTC thermistor that monitors water temperature and provides feedback to the control board for precise temperature regulation throughout the wash cycle.

Thermal Cut-out

Safety device that disconnects power to the heating element if temperature exceeds safe limits (85°C), preventing overheating and potential damage.

Control Board

Main electronic controller that manages heating cycles, monitors temperature sensors, and activates safety protocols in case of heating system faults.

Heating Relay

Electromechanical relay on the control board that switches high current to the heating element based on commands from the microprocessor.

Wiring Harness

High-temperature resistant wiring that connects the heating element to the control board and power supply, designed to withstand moist, hot environments.

Replacement Parts Information

Heating Element

Part No: 00611978 - 2100W stainless steel heating element

Temperature Sensor

Part No: 00645094 - NTC temperature sensor 10k ohm

Thermal Cut-out

Part No: 119476 - 85°C thermal safety switch

Heating Relay

Part No: 00563569 - 16A relay for heating circuit

Wiring Set

Part No: 00611913 - Complete heating circuit wiring harness

Control Board

Part No: 00644253 - Main electronic control unit

Technical Downloads

Bosch SMS40C02GB Documents

Service Manual

Complete technical service manual

Wiring Diagram

Electrical schematics and wiring

Parts Catalog

Complete parts list and diagrams

Error Code Guide

Complete error code reference

Related Model Documents

SMS40C02GB

User Manual & Installation

SMS40C02GC

Similar Model Guide

SMS44GW00G

Related Series Manual

SMS46GW01G

Advanced Model Guide

Note: For technical support or warranty service, contact Bosch Customer Service at 1-800-944-2904 or visit Bosch-home.com