FieldBench
Carrier codes

Carrier

34

Lockout

Ignition prove fail

Trial without flame sense. Repeats → 14.

Walk 34 in Diagnose

7 plates — walk the one on the cabinet

First check

1 Measure µA while it is running

Do not clean first and guess. Series-µA the rod on Carrier 58SP0 during a call. Falling µA is oxide, ground, or a dying flame. A hard drop is often the pressure switch or limit opening, not the rod. HSI, gas cock, manifold, rod, ground.

Expect: Typically ≥ 1.0 µA DC on this family — confirm the door card. Rising while running.

The rest of the walkthrough is Diagnose.

On the plates

  • HSI glow and 120 VAC, gas cock, manifold, flame rod oxide, IFC ground.
  • If flame dies during blower-on delay the IFC may run a 90 s recycle.
  • HSI, gas cock, manifold, rod, ground.
  • Fix 31 metal-vent draft before a fair 34 test.

Plates that use 34

Same number, other makers

34 on Carrier is not the same code on these plates.