16
DSI Sequence of Operation
• Gas Supply
11˝ W.C to solenoid valve is necessary
• 12VDC Battery
Voltage source to water heater
or filtered side
of Convertor
• ON/OFF Switch
It supplies 12VDC to water heater
• Thermal Cut-Off
A one shot heat sensing fuse that’s normally closed and sends power to the thermostat.
When tripped by excessive heat (190°F), (i.e. blocked burner or flue tube) it cuts power to
the circuit board and shuts down ignition.
• Thermostat
A normally closed non-adjustable temperature switch that sends current to the circuit
board. It opens when the water temperature reaches approximately 140°F.
• Circuit Board
The next step is the direct spark ignition system. For a period of 6-8 seconds the circuit
board will send voltage to both the gas solenoid valve and the electrodes. The board is a 3
try for ignition. If ignition does not occur after three tries, the board goes into a lock-out
condition and the non-ignition light illuminated at the
ON
/
OFF
switch.
• E.C.O.
A normally closed safety temperature switch that
sends voltage to solenoid valve. The switch opens if
the water temperature exceeds 180°F.
• Gas Valve
The dual solenoid valve that opens and sends gas to
electrodes when a minimum of 10.5 VDC is applied to it.
• Electrodes
Creates a spark to ignite gas. If the electrodes do not
sense a flame in 6-8 seconds, a signal is sent to the
board to shut the gas valve down and the system goes
into safety lock-out.
NOTE: If this situation exists, the ON/OFF switch must be
turned off and back on again.
