Weil-McLain Series 2 How it works, GOLD CGi Gas-FiredWater Boiler — Boiler Manual, Transformer

GOLD CGi Gas-Fired Water Boiler — Boiler Manual

How it works . . .

①Control 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 49).

②

③

Transformer

The control transformer reduces line voltage to 24 volts for the gas valve and limit circuit.

Inducer

The inducer pulls flue gases through the boiler, causing air to be pulled in through the boiler air openings. The inducer pushes the flue gases through the vent pipe as well.

④Air pressure switch

The air pressure switch signals the control module, telling the control module whether the inducer is working correctly or the vent is blocked.

⑤Water temperature limit switch

The water temperature limit switch turns off the gas valve if the temperature in the boiler goes above its setting. (The circulator will continue to run as long as there is a call for heat.)

⑥Boiler 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.

Other boiler components:

asupply to system

breturn from system

cstainless steel burners

dflue outlet

egas valve

fpressure/temperature gauge

grelief valve

hair vent connection

iflame rollout thermal fuse element (TFE)

jburner shield

kpilot burner and bracket

lgas manifold

mcast iron boiler sections

nflue collector

ojunction box



Part Number 550-110-710/0107