Weil-McLain GOLD CGS-4E - Manual (Page 2)

Part number 550-110-282/1108
2
GOLD CGs-4E Gas-Fired Water Boiler — Boiler Manual
How it works . . .
①
Control module
The control module responds to signals from the room thermostat, air pressure switch and boiler limit circuit to operate
the boiler circulator, pilot burner, gas valve and inducer. When room thermostat calls for heat, the control module starts the
system circulator and inducer.
The control module runs the inducer long enough to purge the boiler flue passages, then opens the pilot valve and activates
pilot ignition spark.
The control module allows up to 15 seconds to establish pilot flame. If flame is not sensed within 15 seconds, the control
module will turn off the gas valve, flash the Flame light, and then enter a 15-second postpurge. The control module will then
start a new cycle. This will continue indefinitely until pilot flame is established or power is interrupted. Once pilot flame is
proven, the control module opens the gas valve to allow main burner flame.
When the room thermostat is satisfied, the control module turns off the gas valve, operates the inducer for a 15-second
postpurge and waits for the next heat call.
The control module indicator lights show normal sequence when the lights are on steady. When a problem occurs, the control
module flashes combinations of lights to indicate the most likely reason for the problem (see page 45).
②
Transformer
The control transformer reduces line voltage to 24 volts for the gas valve and limit circuit.
③
Inducer
The inducer pulls flue gases through the boiler, causing air to be pulled in through the air intake opening. The inducer pushes
the flue gases through the vent pipe as well.
④
Air pressure switch
The air pressure switch signals the control module, telling the control module whether air is moving through the inducer.
⑤
Water temperature limit switch
The water temperature limit switch turns off the gas valve if the temperature in the boiler goes above its setting. (The circula-
tor will continue to run as long as there is a call for heat.)
⑥
Boiler circulator
The boiler circulator circulates water through the external (system) piping. The circulator is shipped loose, and can be mounted
on either the boiler supply or return piping. The factory-installed circulator wiring harness provides ample length for either
location.
NOTE — The control module provides a pump exercising routine. If the boiler is not operated for 30 days, the
control module will power the circulator for 30 seconds, then turn off.
⑦
Timer relay (not visible, mounted below control module on interior panel)
The timer relays delays high fire for 60 seconds.
a supply to system
b return from system
c combustion air inlet
d flue outlet
e gas valve f pressure/temperature gauge
g relief valve (not visible)
h air vent connection
i flame rollout switch
j air inlet box k pilot burner and bracket
l stainless steel burners
m cast iron boiler sections
n flue collector
o junction box
Other boiler components: