Sequence Of Operation Flow Chart - State Water Heaters 60120-100250 Service Handbook

SEQUENCE OF OPERATION FLOW CHART

Sequence is shown with Enable/Disable Switch in the Enable position
If tank temperature drops below Operating Set Point minus
Normal State of all pressure switches and ECO are checked
All other pressure switches and ECO are verified closed
Water is heated to
set point
24 Volt Gas Valve
de-energized
Post-Purge cycle
Water heater goes
into standby mode
6
Differential setting a heating cycle is activated
Control System performs diagnostic checks
Blower Prover pressure switch verified open
Combustion Blower is energized
Pre-Purge cycle
Blower Prover switch contacts confirmed
closed by control system
Spark Ignition Control is energized
24 Volt Gas Valve is energized
gas flows to Main Burner
Is flame sensed at the Main Burner ?
(control system monitors the flame sensor)
YES
Servicing should only be performed by a Qualified Service Technician
NO
NO
NO
24 Volt Gas Valve
de-energized
Inter-Purge cycle
Retries up to
two more times
Control System
Locks Out
"Ignition Failure"
Fault Msg is
displayed
Control System Locks Out
Displays Fault Msg
Control System Locks Out
"Blower Prover Open"
Fault Msg is displayed