Sequence Of Operation Flow Chart - American Water Heater VG6250T100NV Service Handbook

seQuenCe of operation flow Chart

If tank temperature drops below Operating Set Point minus
Differential setting a heating cycle is activated
Control System performs diagnostic system check
Normal State of all pressure switches and ECO are checked
Blower Prover pressure is switch verified open
All other pressure switches and ECO are verified closed
Blower Prover switch contacts confirmed
Igniter is energized for warm up period
Does Control System sense minimum
Does Control System sense minimum flame sensing
of 1.0 µA (DC micro amps) through Flame Sensor?
Water is heated to
set point
24 Volt Gas Valve
de-energized
30 second
Post-Purge cycle
Control System goes
into Standby mode
YES
Combustion Blower is energized
Pre-Purge cycle
closed by Control System
YES
0.5 AC amps through the Igniter?
YES
24 Volt Gas Valve is energized
gas flows to Burner
YES
Servicing should only be performed by a Qualified Service Agent
NO
NO
NO
24 Volt Gas Valve
de-energized
30 second
Inter-Purge cycle
Retries up to
two more times
Control System Locks Out
"Ignition Failure"
Fault Msg is displayed
Control System Locks Out
NO
Displays Fault Msg
Control System Locks Out
"Blower Prover Open"
Fault Msg is displayed
Control System Locks Out
"Low Igniter Current"
Fault Msg is displayed
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