Gas Manifold - A.O. Smith 110 Indoor Service Manual

10-2. Gas manifold

Unit Part #
Function
Failure events
Effects on the water
heater if the manifold
fails
Error codes when the
manifold fails
Diagnostic
Color/Number of wires
Nozzles for gas-rich burners
Nozzles for air-rich burners
Included
AOS Part #
in #102
1. The manifold distributes gas from the gas valves to the burners. The
manifold has two types of the nozzles: one type for gas-rich burners (16
nozzles) and the other for air-rich burners (15 nozzles)
2. There are 3 zones within the manifold, to ensure efficient combustion
operation.
1. Dust deposit on the manifold.
2. Gas leakage from a failed manifold.
3. Ignition failure.
4. Imperfect combustion.
1. The burners cannot receive proper gas flow from the manifold, which can
cause poor combustion in the combustion chamber. In this case, the AFR
rod will detect an improper flame condition and computer will take safety
measures.
2. Gas leakage from the manifold.
10
1. Visual inspection: Excessive dust deposit around the nozzles or cracks on
the manifold.
2. Check voltages and resistance: proper range of values shown below.
Blue-Red
110 Indoor / 110 Outdoor Service Manual
319143-169 (LP)
319143-165 (NA)
11
78 to 100 VDC / 0.9 to 1.7 kΩ
18
CONFIDENTIAL
Ver. 1.01
Checkpoint
12 99
319143-169 (for LP model)
and 319143-165 (for NA
model) is an assembly of
the gas manifold with the
gas valve assembly. For
safety reasons,
assemblies should
installed in the unit as a
whole set.
The gas manifold for the LP
has the "27G" mark, and
the gas manifold for the NA
has the "46B" mark on the
manifold plate.
N/A
these
be