Rinnai INFINITY REU-3203W, Service Manual

Page: 35 / 64

Infinity REU-3203W - 30 - ©Rinnai
6. Thermal Fuse Circuit .
Check the Thermal Fuse.
Disconnect relay connector (F
1
) and measure
resistance between Red and Red.
Normal: < 1
Ω
If normal, replace PCB.
Faulty: Replace Thermal Fuse if after
confirming there is no damage to the
appliance.
7. Overheat Switch Circuit.
Measure resistance between Overheat Switch
terminals (F
2
).
Normal: < 1
Ω
If normal, replace PCB.
Faulty: Replace Overheat Switch.
Note: If Thermal fuse or Overheat Switch
were faulty.
a.) Check heater for damage
b.) Confirm gas type and combustion
dipswitch settings
c.) Confirm test point pressure.
8. Water Flow Sensor
a.)
Measure voltage between Red - Black of
relay connector (E
3
).
Normal: DC 11~13V
If normal, proceed to b .
Faulty: Replace PCB.
b.)
Measure voltage between Yellow - Black
of relay connector (E
3
).
Normal: DC 4~7V
If normal, proceed to 2.
Faulty: Replace water flow sensor.
Note: For controller readout of water flow
whilst operational refer maintenance monitor
(chapter
17) No. 1.