ICP codes

ICP

34

Lockout

Ignition prove fail

Trial without flame sense. Repeats → 14.

Walk 34 in Diagnose

3 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 ICP N80ESN 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 glow and 120 VAC, gas cock, manifold, flame rod, IFC 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, IFC ground.
  • If 31 is also stored, fix draft first or you will never get a fair 34.

Plates that use 34

Same number, other makers

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