49.When power is sent to gas valve 1 it is also sent to time delay relay 1
50.After the
51.Gas valve 1a is energized allowing the remainder of stage 1 to fire.
52.After the
53.After closure of the stage 2 contacts Gas valve 2 is energized.
54.The stage 2 LED on the status display board is now illuminated.
55.The temperature controller closes the stage 3 con- tacts at J3 on the CPW board.
56.Power is applied to pin 5 of the stage 3 connec- tions on the CPW board.
57.Power is applied to the “TH” terminal of ignition module 2.
58.Once the “TH” signal is received at ignition module 2, the heater will perform a
59.If ignition module two locks out, a signal will be sent to the Universal Diagnostics Board and to the status display board to indicate an ignition fault.
60.Once the ignition module determines that the hot surface igniter has heated up and operating prop- erly, a 24 VAC signal is output from pin GV on the module.
61.24 VAC signal is received at gas valve 3 thus ener- gizing it.
62.The stage 3 LED on the status display board is now illuminated.
63.The coil of relay
64.Remote flame sensor 2 is trying to rectify flame.
65.Power is now applied to time delay relay 3 and the contacts of
66.The stage 4 controller contacts close.
67.Power is applied to gas valve 4.
68.The stage 4 LED on the status display board is now illuminated.
69.The heater is now operating at full fire.
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