FieldBench
York codes

York

2 red

Lockout

Pressure switch stuck closed

Draft switch made with inducer off.

Walk 2 red in Diagnose

5 plates — walk the one on the cabinet

First check

1 Unplug the switch with the inducer off

On York TM8T 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 that switch. If the code changes, the switch is welded or the hose is holding residual draft / water.
  • Two-stage: identify which switch (low vs high tap). Do not tee them.
  • IFC input shorted — only after the switch ohms open.
  • Unplug the switch. Water in the hose. Which of the two switches?
  • Unplug the switch. Water in the inducer hose from a long metal run can fake this — still not a 96% collector.
  • 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 2 red