Rheem
12
ProtectLow flame sense
Weak µA.
Walk 12 in Diagnose
8 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 Rheem R801S 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. Rod, ground, manifold.
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
- Rod oxide — non-scratch pad, not sandpaper.
- Chassis ground to burner box and IFC.
- Manifold / orifice / LP conversion.
- Rod, ground, manifold.
Plates that use 12
Same number, other makers
12 on Rheem is not the same code on these plates.