A.O. Smith T-H2-DV User Manual

T-H2-DV/T-H2-OS Service Manual
Ver. 1.01
24
CONFIDENTIAL
10-6. Flame rod
Unit Part # #106 Takagi Part # EKK0E Checkpoint I
Function
To detect flames while unit is in operation.
Failure events
1. Unable to detect flames when flames actually do occur
2. Det
ecting a false flame when no flames actually occur
Effects on the water
heater if flame rod fails
1. The water heater stops operating. The "111” and/or “121” error code(s)
will display.
2. The water heater will not initiate the ignition process. The "721” error
code will display.
Error codes when the
flame rod fails
111 121 721
Diagnostic
1. Visual inspection: connection / breakage of wires or soot buildup on rod.
2. Check Amperes: proper range of values shown below.
Color/Number of wires Orange(17) - Flame rod
(Between flame rod and the
computer board)
(During operation)
More than DC 1 μA
The flame rod is assembled with the AFR rod.
AFR Rod
Flame rod
Leads to computer board
Detecting elements of the flame rod
3/4" (17.5mm)
1/4" (7.5mm)
1/2" (12mm)
1-1/8" (29.3mm)
1-3/4" (44mm)

A.O. Smith T-H2-DV Specifications

General

Brand	A.O. Smith
Model	T-H2-DV
Category	Water Heater
Language	English