Viessmann · Boiler

F.454 Wrong BCU software version

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

Incorrect BCU software

Test and repair steps

Flash the BCU with the correct software version.

Models that show this code

4 models in Vitodens 200-W B2HE

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

Other codes on the same units

F.450 Program run monitoring error
F.451 Program run monitoring error
F.452 Program run monitoring error
F.453 Sequence synchronization error
F.455 Program run monitoring error
F.456 Program run monitoring error
F.457 Fan sluggish or blocked
F.458 Reset sequence fault

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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.