Electrical Component Analysis - Rinnai REU-2018W Service Manual

22. Electrical Component Analysis

Before starting inspection, re-check wiring harnesses and double check that all connections are tight.
Before carrying out checks marked with *, remove power cord from wall plug.
Examination
Nature of Fault
A. The ON indicator 1. Is the power cord
does not light up after plugged in?
switching the unit on.
2. Is supply voltage cor-
rect?
3. Check 3 Amp electri-
cal fuses.
4. Check 3 Amp electri-
cal fuses.
5. Check for short cir-
cuits.
6. Check 240V-100V
transformer.
7. Check the remote
control (where con-
nected).
B. Digital monitor
1. Check water flow
lights up, but
sensor.
combustion does
not commence.
(When remotes
are connected)
Error code "72" dis- 2. Check flame rod.
played on digital moni-
tor
Infinity REU-2425W
Diagnostic Point
Point
Inspect visually
Measure voltage at power
point.
*Inspect visually
* Disconnect and measure
resistance to confirm if fuse is
blown. Normal< 1 M
i) Measure the resistance of
each solenoid valve.
* Remove connector I
from the PCB before measur-
ing.
Pink - Black
0.9 ~ 1.3 k
Yellow - Black
1.3 ~ 1.9 k
Blue - Black
1.5 ~ 1.9 k
ii) Measure the sparker resist-
ance.
* Disconnect the sparker con-
nector I and measure the
4
resistance between both termi-
nals.
iii) Check wiring
i) Measure voltage between
red-red A connector.
1
ii) Measure voltage at connec-
tors A, F with appliance on
"standby".
A, Green-Green
AC16 ~ 20 V
F, Orange-Orange
AC13 ~ 30 V
F, Brown-Grey
AC30 ~ 50 V
F, Yellow (LH)-Grey
AC180 ~ 220 V
Measure voltage between the
control terminals at H
i) Measure voltage between
red-black at connector C
ii) Measure voltage between
yellow-black at connector C
* Measure resistance between
flame rod terminal A
earth.
Values
Is it plugged in?
AC 240 V
(NZ 230 V)
Is the surge protector
indicator lit up
Is fuse blown?
Ω
Are values within
those specified at left?
N.B. Measure after
checking that there
are no broken wires
or shorts.
Ω
Ω
Ω
Ω
Is resistance > 1M
Are there any shorts?
AC 90~110 V
Are values within
those specified at left?
DC10 ~ 13 V.
.
1
DC11 ~ 13 V.
2
DC2 ~ 10 V
2
Ω
Resistance > 1M
and
2
- 40 -
Y/N Action
Yes Go to A - 2.
No Plug in cord
Yes Go to A - 3.
No Check power supply
circuit.
Check fuses.
Yes Go to A - 5
No Go to A - 6
Yes Go to A - 5 and replace
fuse.
No Go to A - 6.
Yes Go to A - 6 - 2)
No Replace faulty solenoid
valves.
Yes Go to A - 5-iii)
No Replace sparker
Yes Rectify/Replace
No Replace PCB
Yes Go to A - 6 - ii)
No Replace PCB.
Yes Go to A - 7.
No Replace 240V trans-
former.
Yes Check cable for shorts/
broken wires; replace
remote control.
No Replace PCB.
Yes Go to B - 1 - ii)
No Replace PCB
Yes Go to B - 4 - ii).
No Replace water flow sen-
sor.
Yes Replace PCB.
No Replace flame rod.
Issue 2 - 5/07/04 ©Rinnai
Repair
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