FieldBench
Trane codes

Trane

E3.1

Lockout

Shorted first-stage pressure switch

Trane Link-enabled alarm table: first-stage PS is shorted / already made when the IFC expected it open.

Walk E3.1 in Diagnose

2 plates — walk the one on the cabinet

First check

1 Unplug the switch with the inducer off

On Trane S8V2 this code is the switch made when the inducer is not running. Unplug that switch only. This is Category I metal vent. There is no 96% collector or PVC trap to prime.

Expect: Code changes when the harness is open.

If fail: Wrong switch, or the IFC input is shorted.

If pass: Switch/hose path. Go to step 2.

The rest of the walkthrough is Diagnose.

On the plates

  • Unplug the first-stage switch. If the code changes, the switch is welded/shorted or the hose is holding residual draft or water.
  • If the code does not change with the switch unplugged, the IFC input or harness is shorted.
  • Confirm it is the FIRST-stage switch and hose, not the high-fire pair.
  • Do not treat E3.1 as an open/draft fault. That neighborhood is E3.2 if THIS door card shows it.
  • This is Category I metal vent. There is no 96% collector or PVC trap to prime.
  • Cap, liner, common-vent tables, inducer wheel, hose on the inducer housing.

Plates that use E3.1