Bosch · Tankless water heater

HS HS about

Menu / mode display Bosch Greentherm T9800 SEBosch Greentherm T9900 SE

What the display is showing

Shows the software and hardware versions installed in the water heater.

Applies to: Greentherm T9800 SE 160/199 and T9900 SE 160/199 tankless water heaters

What to do

Open P4 Information and select HS About

Models that show this code

6 models in Bosch Greentherm T9800 SE, Bosch Greentherm T9900 SE

Greentherm T9800 SE 160Greentherm T9800 SE 199Greentherm T9800 SEC 199Greentherm T9900 SE 160Greentherm T9900 SE 199Greentherm T9900 i 199

Other codes on the same units

Error reset Hold ON/OFF key to clear an error code
FA Gas leak in the gas path
FC Touch key held over 20 seconds
FH FH failure history
OD OD operation data
Open Taps Open Taps message during auto adjust
PA PA water actuator (valve calibration)
PE PE appliance type (read-only data)

Save it for the next call

Star this code in the HVACopedia app and keep the whole library on your phone for jobs with no signal.

Open the app

Source: Bosch Greentherm T9800 SE 160-199 installation 6720816815 (06.2023), 6.5 Information / Adjustments menu pp.47-48; T9900 SE 160-199 installation 6 720 813 635 (2024-06) same section. Summarized in our own words; check the original manual for your model.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.