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Viessmann · Boiler

F.446 Supply sensor / high limit deviation

High severity Vitodens 200-W B2HE

What the control is telling you

Burner in a fault state.

Applies to: Vitodens 200-W B2HE 85, 120, 150, 199

Likely causes

  • Sensor deviation
  • Plug/lead fault

Test and repair steps

  1. Check the supply temperature sensor/high limit and its plug and lead.
  2. Reset the appliance.

Models that show this code

4 models in Vitodens 200-W B2HE

B2HE-120B2HE-150B2HE-199B2HE-85

Other codes on the same units

  • F.417 BCU faulty
  • F.418 BCU faulty
  • F.425 Time synchronization failed
  • F.430 Gateway communication error
  • F.447 Ionization current signal deviation
  • F.448 Ionization current signal deviation
  • F.449 Program run monitoring error
  • F.450 Program run monitoring error

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Source: Viessmann Vitodens 200-W B2HE 85/120/150/199 Service Instructions 6167 813-24 (09/2026), Fault messages, p.62-73. 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.