FieldBench
Bosch codes

Bosch

H8

Lockout

Pressure transducer

Suction PT failed or disagrees with gauges.

Walk H8 in Diagnose

Sign in for the next measurement

First check

1 Heat rejection first

On Bosch BOVA 2.0 high pressure is outdoor airflow until proven otherwise. Fan running the right direction, coil clean, fins not folded, no recirc over a fence or through a garage. PT wiring. Idle PT vs manifold (±50 psi class on IDS).

Expect: OD fan on, coil clean, discharge air leaving the top/side freely.

The rest of the walkthrough is Diagnose.

On the plates

  • PT wiring. Idle PT vs manifold (±50 psi class on IDS).
  • Supply ~5 VDC on the transducer reference. Bad PT vs bad board.

Plates that use H8