Bosch Error Code

Bosch Code F7 — Control Board (PCB) Fault

Code F7 is control board failure. Erratic behavior, multiple unrelated codes, dealer-only replacement.

Updated May 2026 · Bosch Water Heaters

Code F7 = Control board (PCB) fault. The unit's central computer is reporting an internal error.

Diagnose by elimination

PCB failure is the diagnosis of last resort. PCBs are robust and rarely fail before year 8-10. Work through other possibilities first:

  • Sensor wiring (loose connectors)
  • Power surge damage (recent storm or breaker issue)
  • Firmware corruption (rare; may resolve with Level 2 power cycle)

Confirm PCB failure

  • Multiple unrelated error codes in rapid succession
  • Display garbled or blank with power confirmed
  • Random restarts mid-operation
  • Buttons not responding

Replacement

Dealer-only. PCBs come pre-flashed with model-specific firmware. Cost: $400-800 OEM + $250-500 labor.

Warranty

5-year parts warranty includes PCB. Outside warranty, replacement is 30-40% of new unit cost.

Bottom line

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