34
TM061 Rheem 27 Water Star Service Instructions
– Issued: 11/10
REV A Issued 08/13
This document is stored and maintained electronically by
Service. Al
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Fault Finding Test 15
Test 15
Isolate power before conducting test.
Using a multimeter set on the ohms scale,
measure the resistance at terminal P whilst
unplugged from the PCB.
Maintenance display code
Test Point
Measured Value
2y: Ambient Air Thermistor
7 Blue & 3 Black
@20ºC
– 10.3 kilo-ohms
@40ºC
– 4.9 kilo-ohms
3y: Cold Inlet Thermistor
6 White & 3 Black
4y: Heat Exchanger Thermistor
5 Yellow & 3 Black
5y: Hot Water Outlet Thermistor
4 Red & 3 Black
Error Code 16
Outlet water temperature is too hot.
Error Code 16*
The gas booster should not
operate with an inlet temperature
in excess of 58
o
C.
*Error 16 will occur if the unit heats the
water to 20
o
C above the set point
– 3
o
C
eg: 60 + 20
– 3 = 77
o
C.
**Is the unit used as an
in-series gas booster?
** 276, 866, 876 series heaters are
unsuitable for use as in-series gas boosters.
Is the inlet water
temperature >58
o
C?
Replace control PCB.
Is the resistance of the
proportional gas valve
correct?
TEST 12
Replace the gas valve assembly.
YES
YES
NO
NO
YES
NO
Is the resistance of the cold
water inlet thermistor normal?
TEST 15
YES
Replace cold water inlet
thermistor.
NO
Is the resistance of the hot
outlet thermistor normal?
TEST 15
Replace hot outlet thermistor.
NO
Is the resistance of the heat
exchanger thermistor normal?
TEST 15
Replace heat exchanger
thermistor.
NO
YES
YES
SW2
SW1
4
3
2
1
6
5
G
Y
9
O
N
5
6
7
8
1
2
3
4
BK
R
BR
W
O
BL
4
3
2
1
W
Y
5
6
7
2
4
BL
R
BK
BK
R
7 8
6
5
4
3
W
G
BR Y
R
BK
K
1
P