Bosch Part Subpage

Bosch PCB Control Board — Failure & Replacement

Bosch PCB failure modes, symptoms, and dealer-only replacement.

Updated May 2026 · Bosch Water Heaters

The Bosch PCB is the unit's central computer. Failure causes erratic behavior and unusual code combinations.

Symptoms suggesting PCB failure

  • Multiple unrelated error codes
  • Display garbled or blank
  • Random restarts
  • Modulation not happening

Cost

  • OEM PCB: $400-800
  • Labor: $250-500
  • Total: $650-1,300

Bottom line

10+ year-old unit with PCB failure → replacement makes more sense than repair. Inside warranty → replace PCB.