T-M50 / T-M50 ASME Service manual
Ver. 1.05
17
CONFIDENTIAL
10-3. Fan motor
Unit Part #
#416
AOS Part #
EKK25
Checkpoint
G
Function
To provide combustion air into the combustion chamber and to exhaust flue gas.
Failure event
1. Fan speed failure, causing abnormal sounds with or without combustion during
operation.
2. Unexpected activation caused by the connectors of the fan motor getting wet.
3. Disconnects from the bottom of the combustion chamber.
Effects on the water
heater if fan motor fails
1. The water heater does not function properly
2. Failure to ignite or abnormal ignition
3. Unstable combustion conditions
Error codes when the fan
motor fails
101 111 121 611 991
Diagnostic
1. Visual inspection: connection/breakage of wires or dust (causing electrical
shortage)
2. Voltage check: proper range of voltages shown below.
Red-Blue
110 to 160 VDC (Input)
Yellow-Blue
13 to 17 VDC (Input)
Orange-Blue
2.0 to 6.5 VDC (Input)
Color/Number of wires
White-Blue
Verify the fan motor speed using the Diagnostics Mode of the
temperature remote controller. See Section 12-1 for details.
Fan damper (#138 / EK270)
1 - 3/
4 "(
4 4 mm
)
PWN turbo fan motor
6
-
1
/
2
"
(
1
6
5
.5
m
m
)
3 - 3 / 4 "( 9 5 .1 5 m m )
O p e n i n g 2 - 1 / 8 " ( 5 4 m m )
The fan damper
is not included in
EKK25.
