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Bosch · Tankless water heater

FC Touch key held over 20 seconds

Low severity Bosch Greentherm T9800 SEBosch Greentherm T9900 SE

What the control is telling you

A key on the touch display has been pressed continuously for more than 20 seconds.

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

Likely causes

  • Dirty or wet display
  • Object resting on the key

Test and repair steps

  1. Release the key and clean the display.

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

  • CE Flue blockage during operation (siphon pressure)
  • CF Flue blockage during operation (insufficient air)
  • EA Ignition failure
  • EB Control unit internal error
  • EC Flame lost during operation
  • EE Gas valve modulation coil disconnected
  • EF Wrong gas type configured
  • FA Gas leak in the gas path

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Source: Bosch Greentherm T9800 SE 160/199 installation 6720816815 (06.2023), Table 24 Error code diagnostics, p.65-69; Bosch Greentherm T9900 SE 160/199 | i 199 installation 6 720 813 635 (2024-06), section 9.1 Error code diagnostics, p.68-73. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

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.