Abnormal Fan Motor - A.O. Smith ATI-140H-N Service Handbook

3. If the unit was recently rebuilt,
make sure that each gas valve wires
are plugged into the proper place.
4. Verify that the supply gas pressure
is within the specified limits. Too
high of an inlet gas pressure may
cause the main gas valve to jam or
could be damaged.
5. Check the voltage across each
solenoid gas valve wire during
operation. The blue wire is
common.
•
SV1: Green, #9
•
SV2: Orange, #53
•
SV3: Red, #73
The voltage reading should be
93-120 VDC. If the voltage is not
TABLE 3: RESISTANCE VALUES OF THE TEMPERATURE THERMISTORS INDOOR AND OUTDOOR MODELS
°F
TEMPERATURE
°C
RESISTANCE KΩ
°F
TEMPERATURE
°C
RESISTANCE KΩ
TABLE 4: RESISTANCE VALUES OF THE TEMPERATURE EXHAUST THERMISTOR INDOOR MODELS ONLY
°F
TEMPERATURE
°C
RESISTANCE KΩ
°F
TEMPERATURE
°C
RESISTANCE KΩ
within normal range, replace the
computer board, part number
320273-369.
6. With the power off, check the
resistance of the valve. Normal
resistance reading for SV1 and SV2
is 1.35-1.65 kΩ. Normal resistance
reading for SV3 is 2.07-2.53 kΩ.
If the resistance is out of range,
replace the gas valve, NG: part
320273-356, LP: part 320273-354.

Abnormal Fan Motor

Error Code: 611
1. Turn off power supply.
2. Check fan motor wiring for
breakages, burn marks on the
32 41 50
0 5 10
23.76 19.08 15.43
122 131 140
50 55 60
3.49 2.96 2.53
32 41 50
0 5 10
30.04 24.12 19.50
122 131 140
50 55 60
4.41 3.74 3.19
59 68 77
15 20 25
12.56 10.28 8.47
149 158 167
65 70 75
2.16 1.86 1.60
59 68 77
15 20 25
15.87 13.00 10.71
149 158 167
65 70 75
2.73 2.35 2.03
Condensing Models: On-Demand Water Heater Service Handbook • 15
computer board (PCB), or moisture.
If moisture is found, allow the
connection to dry completely
before turning power back on.
3. Check fan housing for water. If
found, please dry the fan, then
test heater. If there is a significant
amount of water, there may be a
heat exchanger leak.
4. To remove the fan, follow steps
1 through 10 in ""Removing Heat
Exchanger Components (Indoor
Models)" (p. 37). When you are
finished, reassemble in reverse
order.
5. If the 611 error code still appears after
all items have been checked, the PCB
may need replacement. Contact the
technical service department.
86 95 104
30 35 40
7.02 5.85 4.90
176 185 194
80 85 90
1.39 1.21 1.05
86 95 104
30 35 40
8.87 7.39 6.19
176 185 194
80 85 90
1.76 1.53 1.33
113
45
4.12
203 212
95 100
0.92 0.81
113
45
5.21
203 212
95 100
1.16 1.02