Heat Exchanger - A.O. Smith 710 ASME Service Manual

10-7. Heat exchanger

Unit Part #
Function
Failure event
Effects on the water
heater if the heat
exchanger fails
Error codes when the
heat exchanger fails
Diagnostic
Color / Number of wires
ASME Model
#210 (Regular model)
#211 (ASME model)
Absorbs heat from combustion and transfer it to water through the heat
exchanger pipes.
1. Clogged heat exchanger fins and/or cracks on the heat exchanger walls.
2. Leaking exhaust gas.
3. Improper heat transfer can cause the water in heat exchanger to boil.
1. Water leakage from the heat exchanger
2. Exhaust gas leakage (if this occurs, an overheat cutoff fuse is in place to
detect this event and immediately stop the water heater from operating)
3. Abnormal sounds during combustion
1. Visual inspection: soot deposits, cracks on the heat exchanger walls,
and/or water leakage from the heat exchanger.
2. In the event of abnormal sounds during combustion:
A. Inspect for soot buildup inside the heat exchanger.
B. Inspect for scale buildup inside the heat exchanger pipes. Scale
buildup obstructs proper heat transfer to the water, thereby overheating
the heat exchanger and causing damage.
Only the ASME model has a plate as shown in the
drawings below. The configuration and material of
the ASME model heat exchanger are different from
the regular model, as well.
710 / 710 ASME Service Manual
319143-302
(Regular model)
AOS Part #
319143-314
(ASME model)
N/A
N/A
Regular model
9 - 1 / 4 " ( 2 3 5 . 6 m m )
21
CONFIDENTIAL
Ver. 1.00
Check
N/A
point