T-M50 / T-M50 ASME Service manual
Ver. 1.05
21
CONFIDENTIAL
10-7. Heat exchanger
Unit Part #
#401 (Regular model)
#444 (ASME model)
AOS Part #
EM308
(Regular model)
EM323
(ASME model)
Checkpoint
N/A
Function
Absorbs heat from combustion and transfer it to water through the heat
exchanger pipes.
Failure event
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.
Effects on the water
heater if the heat
exchanger fails
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
Error codes when the
heat exchanger fails
N/A
Diagnostic
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.
Color/Number of wires
N/A
Regular Model
ASME Model
0 M 5 A
(M a nu fa ct ur e)
Plate
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.
