Bosch Tankless Water Heater: Clear an error code with the ON/OFF key
Clear an error code with the ON/OFF key on a Bosch tankless water heater: Holding ON/OFF for over 3 seconds clears an error code from the display; the appliance then runs its start-up sequence. If the error returns, call a licensed professional.
Applies to: Greentherm T9800 SE 160/199 and T9900 SE 160/199 tankless water heaters
How to fix clear an error code with the on/off key: step by step
- Touch and hold the ON/OFF key for more than 3 seconds
- Wait for the start-up sequence
If the unit shows an error code, look it up: Bosch Tankless Water Heater codes
Models
Bosch Greentherm T9800 SE
Greentherm T9800 SE 160Greentherm T9800 SE 199Greentherm T9800 SEC 199
Bosch Greentherm T9900 SE
Greentherm T9900 i 199Greentherm T9900 SE 160Greentherm T9900 SE 199
Source: Bosch Greentherm T9800 SE 160-199 installation 6720816815 (06.2023), 6.3 Error code reset p.45; T9900 SE 160-199 installation 6 720 813 635 (2024-06) same section. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.