Infinity REU-VRM3237WG / HD250e REU-VRM3237WC - 24 - Issue 1 - 19/05/09 ©Rinnai
9. Water Flow Servo Circuit (G
6
)
a.) Disconnect relay connector (G
6
), and measure resistance between Red and Blue of
Water Flow Servo.
Normal: 10~30
If normal, proceed to b.
Faulty: Replace Water Flow Servo and W
ater Flow Sensor.
b.) Disconnect relay connector (G
6
), and measure voltage between Orange (+) and Grey
(-) on PCB unit side.
Normal: DC11~13V
If normal: proceed to c).
Faulty: Replace PCB u
nit.
c.) Measure vo
ltage between Brown and Grey with relay connector (G
6
) connected (with
no water flowing, water flow servo fully open).
Normal: DC4~6V
Faulty: Replace Water Flow Servo with W
ater Flow Servo.
d.) Measure voltage between Yellow and Grey with relay connector (G
6
) connected (with
no water flowing, water flow servo fully open).
Normal: < DC1.0V
Faulty: Replace Water Flow Servo and W
ater Flow Sensor.
10. Heat Exchanger Outlet Thermistor Circuit (G
4
)
Check Heat Exchanger Outlet Thermistor if error indicator “33” is displayed.
Disconnect relay connector (G
4
) and measure resistance between White and Pink.
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 temperature whilst operational refer
maintenance monitor (chapter 17
) No. 11.