Rinnai REU-V1620WG Service Manual page 26

7. Flame Rod Circuit
Operate appliance and check flame rod (I
Check Dc current flow between yellow flame rod wire and earth is over DC1µA
Disconnect flame rod terminal (I
"72" indicated:- Proceed to c).
"72" is not indicated:- check for electrical leaks from the flame rod circuit.
Measure voltage between flame rod terminal (I

Normal: >1M
If normal, Check all power inputs into PCB. If power inputs okay replace PCB.
If resistance abnormal replace flame rod.
a) Remove the Flame Rod terminal (I
again check the Hot water outlet thermistor.
If "72" is not displayed check current leakage from the Flame Rod.
b) Measure voltage between body earth and Flame Rod terminal (I
Normal: voltage AC100~160V
If normal, check all power inputs into PCB. If power inputs okay replace PCB.
Faulty: Replace Flame Rod.
c) Check if the Flame Rod is securely fitted.
Normal: Check all power inputs into PCB. If power inputs okay replace PCB.
Faulty: Adjust the fitting of the Flame Rod.
Check all appliance earth connections are clean and secure.
8. Thermal Fuse Circuit
Check the Thermal Fuse.
Disconnect relay connector (I
(16 Series) - White-Red
(20 Series) - Black-Red
(24/26 Series) - Blue-Red.

Normal: < 1
If normal, replace PCB.
Faulty: Replace Thermal Fuse if after confirming there is no damage to appliance.
9. Water Flow Sensor
a) Measure voltage between Red-Black of relay connector (E
Normal: DC 11~13V
If normal, proceed to b).
Faulty: Replace PCB.
b) Measure voltage between Yellow-Black of relay connector (E
Normal: DC 4 ~ 7 V
If normal, proceed to 2.
Faulty: Replace water flow sensor.
Note: For controller readout of water flow whilst operational refer maintenance monitor.
(Chapter 15) No. 1.
REU-V1620WG / REU-V1620WB / REU-V1620WS / REU-V2024WG - 21 -
)
4
), and re-operate appliance.
4
) and appliance earth.
4
) repeat appliance operation procedure, if "72" is displayed
4
) & (E ) measure resistance between:
1 1
).
4
).
2
).
2
Issue 1 - 6/04/09 ©Rinnai