Cumberland VariFlame VF-16-ONG, Owner'S Manual

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Chapter 3: System Overview
Power up and Initialization
When you first turn on the VariFlame, it performs a self-check routine before starting up. If the following
problems are detected, the controller goes into lockout mode:
• A memory issue
• AC frequency issue on the main sector
• A firmware register issue
• An input is not in the right state
• If the controller does not need the fan and heater, it stays in an idle state. In this state, the controller
does not use the fan.
Fan start and run
When the fan is needed, it turns on. The controller verifies the air switch to confirm the fan is running. If it
isn’t working, the controller goes into lockout mode. If the fan is working, it remains even if the heating is
not requested.
Heater ignition sequence and ignition retries
During the ignition stage of the heater, the controller starts the igniter, waits 4 seconds, starts the fan and
then verifies the valve relays for possible short circuits before activating them. If any short circuit is
detected, the controller goes into lockout mode. If everything is fine, the gas valves are energized. The
controller verifies if the gas valve is energized after 4 seconds. If the gas valve is energized, it verifies the
stability of the flame for 6 seconds. If the flame is stable, the burner is considered on. If at anytime during
this process, the gas valve is not found to be energized or the flame is unstable, the controller makes 3
attempts at ignition. If after the third attempt ignition still fails, the controller goes into lockout mode.
The heater remains ignited until heating is no longer needed or the flame is lost.
Cool down and post purge handling
When the heater is no longer needed, the valve is de-energized. The controller verifies if the gas valve is
de-energized. If it is the case, the controller makes a cool down and a post purge for a period of 5 sec-
onds. Otherwise, the controller goes into lockout mode. After executing a cool down and a post purge for
a period of 5 seconds, the controller turns off the fan. The controller verifies if the air switch is opened. If
the air switch is closed, the controller goes into lockout mode. If all is fine, the controller goes into an idle
state.
Safety Lockout
If the controller detects a safety gas issue, all outputs are turned off and the LED “LOCKOUT” turns on.
The controller stays in this state until you manually shut the controller off and restart it.
Flame sensor tests
The flame sensor is tested at the start-up and at periodic intervals to verify if the flame sensor input works
correctly.
22 PNEG-2091 VariFlame™ Heater