32
Part Number 550-142-785/0812
GWI
Series 2
Gas-Fired Water Boilers –
Boiler Manual
Control module
Solder or water
splatter between plugs and circuit
board can cause improper operation of control
module. Place a shield over the boiler internal con-
trols and components during installation. Failure to
comply could result in severe personal injury, death
or substantial property damage.
Make sure
ground wiring
is installed per wiring
diagram. Good grounding is extremely important
for proper operation.
Control indicator lights —
LOCKOUT modes
See
Charts 1
through
7
in this section for detailed trouble-
shooting procedures.
Control indicator lights —
HARD LOCKOUT Summary (Flashing LED’s)
MAY remove 120VAC power for more than 2 seconds to clear
lockout OR ignition control will automatically restart sequence
of operation after 1 hour waiting period after fault condition is
cleared.
12 Troubleshooting – components
(continued)
INDICATOR LIGHT
CONDITION
POWER
Flashes once per second
120 VAC connection to
boiler
reversed.
Flash code 2*
Internal fault, icroprocessor
or
memory.
Flash code 3*
Unused.
Flash code 4*
Unused.
Flash code 5*
Internal fault, water
thermistors
disagree.
Flash code 6*
Internal fault, gas valve
circuit.
* Flash code pattern: POWER LED flashes 2, 3, etc. times
rapidly followed by 2 seconds off, then repeats.
SOFT LOCKOUT Summary (Flashing LED’s)
MAY remove 120VAC power for more than 2 seconds, cycle
thermostat for between 2 and 20 seconds, OR ignition control
will automatically restart sequence of operation after 1 hour
waiting period.
INDICATOR LIGHT
CONDITION
POWER + TSTAT/CIRC
High voltage detected on TSTAT circuit.
POWER + PURGE
Pressure Switch stuck open or closed.
POWER + FLAME
Flame sensed without call for heat or out
of sequence during ignition trial.
CAUTION Summary (Flashing LED’s)
INDICATOR LIGHT
CONDITION
PURGE
Pressure switch opened after it had been
proven
closed.
LIMIT
Fault detected in temperature sensing
hardware.
FLAME
Flame loss or flame not sensed during
trial
for
ignition.
Troubleshooting the control module
See
Figure 23
, page 33, for location of harness plug receptacles
and plugs on the control module.
Sensor resistance values
Temp
(°F)
Sensor ohms
Temp
(°F)
Sensor ohms
Min
Max
Min
Max
32
34265
37871
120
4517
4992
40
27834
30764
130
3698
4088
50
21630
23907
140
3043
3364
60
16944
18727
150
2517
2782
70
13372
14780
160
2091
2311
80
10629
11747
170
1744
1928
90
8504
9399
180
1461
1615
100
6847
7568
190
1229
1359
110
5545
6129
200
1038
1147
Temperature sensor
1. The boiler temperature sensor is a resistance-type device.
2.
The Chart below shows the correct value for the sensor at
various temperatures.
3.
Use the resistance values at 32°F, 60°F, 70°F and 212°F to
measure the sensor resistance at known temperatures (ice
point, room temperature and sea level boiling point). For ice
point and boiling point, insert the sensor in water at that tem-
perature. Use an ohmmeter to read resistance value between
thermister # and thermistor common. See Figure 30, page 50,
for sensor plug details.
Sensor resistance values
Figure 22 Control module
