Rinnai INFINITY REU-3203W Service Manual page 36

9. Water Flow Servo Circuit
10.Heat Exchanger Outlet ThermistorCircuit
Infinity REU-3203W
a.)
Disconnect relay connector (B
measure resistance between Red and Blue
of Water Flow Servo.
Normal: 10~30
If normal, proceed to
Faulty: Replace Water Flow Servo and
Water Flow Sensor.
b.)
Disconnect relay connector (B
measure voltage between Orange (+) and
Grey (-) on PCB unit side.
Normal: DC11~13V
If normal: proceed to
Faulty: Replace PCB unit.
c.)
Measure voltage between Brown and
Grey with relay connector (B
(with no water flowing, water flow servo
fully open).
Normal: DC4~6V
Faulty: Replace Water Flow Servo with
Water Flow Servo.
d.)
Measure voltage between Yellow and
Grey with relay connector (B
(with no water flowing, water flow servo
fully open).
Normal: < DC1.0V
Faulty: Replace Water Flow Servo and
Water Flow Sensor.
Check Heat Exchanger Outlet Thermistor if
error indicator "33" is displayed.
Disconnect relay connector (E
resistance between White and White.
Circuit Break: Resistance > 1M
Short circuit: Resistance < 1
If normal, proceed to Water Flow Servo
Circuit
If faulty, replace Heat Exchanger Outlet
Thermistor.
Note: For controller readout of thermistor
teperature whilst operational refer
maintenance monitor (chapter 17) No. 11.
- 31 -
), and
2
Ω
b
.
), and
2
c .
) connected
2
) connected
2
) and measure
2
Ω
Ω
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