What does 'Box temperature protection' mean on my Bosch Water Heater?
- CCindy ShepherdSep 12, 2025
If the temperature inside the appliance box exceeds 70ºC, it triggers box temperature protection. The error is resolved by a manual reset.
What does 'Box temperature protection' mean on my Bosch Water Heater?
If the temperature inside the appliance box exceeds 70ºC, it triggers box temperature protection. The error is resolved by a manual reset.
What to do if my Bosch WTD 12-3 AME 31 Water Heater has exhaust blockage?
If the fan speed and/or consumption detect a pressure above normal operating conditions on the exhaust, check configuration parameters like AS (altitude), F9 (flue exhaust code), AP (appliance power), etc.
What to do if my Bosch WTD 12-3 AME 31 shows temperature limiter or thermal fuse opened circuit?
This error occurs if the temperature limiter detects a temperature over 85ºC, or if the thermal fuse contact opens (192ºC) due to overheating and malfunction of the temperature limiter. The error is resolved by manually resetting the system after the temperature limiter cools down and the contact closes again.
Why does my Bosch WTD 12-3 AME 31 Water Heater display a water flow signal over specified maximum value?
This error occurs when the water flow exceeds 22 l/min. The error is resolved when the water flow is below this value again.
What to do if my Bosch WTD 12-3 AME 31 Water Heater shows a gas valve wrong connection?
If a safety solenoid from the gas valve is disconnected, the error can be resolved by a manual reset.
What causes the 'Wrong gas type' error in my Bosch Water Heater, and how do I fix it?
If an output higher than expected is obtained, it indicates the wrong gas type is being used. The error is resolved by performing a manual reset.
What does it mean when my Bosch WTD 12-3 AME 31 displays MCU RAM DC (micro controller) internal error?
Check if the voltage is too low (less than 70V AC). This error is resolved by a manual reset. If the voltage is okay and the error persists, replace the control unit.
Why does my Bosch Water Heater show an error related to the temperature limiter or thermal fuse?
If the temperature limiter detects a temperature over 85ºC, it causes the temperature limiter or thermal fuse to open the circuit. This error is resolved by manually resetting the system after the temperature limiter cools down and the contact closes again.
What to do if my Bosch WTD 12-3 AME 31 displays an internal checking failure?
This error is resolved by a manual reset. If the error persists, replace the control unit.
What to do if my Bosch WTD 12-3 AME 31 Water Heater remote controller removes the error code 5 times continuously within 15mins?
This error is resolved by a manual reset.
Gas Type | Natural gas |
---|---|
Ignition Type | Electronic ignition |
Frequency | 50 Hz |
Type | Flow-through water heater |
Mounting Type | Wall mounted |
Thermostat | Yes |
Safety Features | Flame failure device, overheating protection |
Explains the function of the control panel for user, installer, and technician operations.
Describes the heat cell, including heat exchanger, burner, and electrodes.
Details the turbine flow sensor, its operation, and characteristic curve.
Explains the ignition electrode's function in spark generation and safety timing.
Describes the ionization electrode's role in sensing flame presence.
Details strategies for reducing power to prevent overheating and scalding.
Presents the electrical diagram and components of the MPP electronic control unit.
Presents the electrical diagram and components of the LPP electronic control unit.
Outlines procedures for entering service mode and performing configurations.
Details adjustments for minimum/maximum power operation.
Guides on accessing combustion adjustment parameters.
Adjusts maximum burner power after component replacement or conversion.
Adjusts minimum burner power after repairs or conversion.
Accesses diagnostic and visualization data for troubleshooting.
Lists the last 10 recorded failures for diagnostic purposes.
Provides recommendations for appliance checks and servicing.
Lists error codes and their definitions for troubleshooting.
Categorizes error codes as self-resolving or requiring action.
Describes troubleshooting for defective water temperature sensors.
Explains actions taken for box over-temperature protection.
Details issues with open circuit air temperature sensors.
Describes troubleshooting for defective outlet water temperature sensors.
Explains troubleshooting when no fan signal is received.
Addresses issues with water flow signals exceeding specified maximum values.
Explains troubleshooting for exhaust blockage detection.
Details actions for detected over-temperature conditions.
Describes troubleshooting for defective inlet water temperature sensors.
Troubleshoots open circuits in temperature limiters or thermal fuses.
Addresses the error when no ionization signal is detected during safety time.
Explains errors related to incorrect gas valve connections.
Details issues arising from an incorrect gas type setting.
Describes troubleshooting for ionization errors.
Explains how to detect and resolve gas valve leakage.
Addresses issues related to ionization signal loss.
Troubleshoots errors in the solenoid valve drive circuit.
Addresses errors in the micro controller's instruction processing.
Troubleshoots errors in instruction compilation and execution.
Addresses internal errors in the micro controller's RAM.
Troubleshoots short circuit errors in APS I/O.
Addresses errors in the micro controller's ROM.
Troubleshoots registration errors in the micro controller.
Addresses errors related to the remote controller function.
Troubleshoots self-check errors within the PCB.