Fault Code A1

Fault: The temperature within the hot water unit is hotter than average.

Applies to: Bosch Tankless Water Heaters

Error codes are the indicators of the problems inside the water heater. When the error code appears on the Bosch heater’s LCD display, something may need to be repaired or isn’t functioning properly. Each error code has a meaning to help you understand the problem and what needs to be done to fix it.