Instructions / Assembly

26
Sequence of Operation
1. During initial start-up or a call for heat,
the control will verify the vacuum switch
is open.
2. Once the control verifies the blower
vacuum switch is open, the control will
energize the blower motor for the pre-
purge sequence (approximately 5 seconds).
3. The control will verify the blower vacuum
switch has closed, ensuring that the
blower is functioning properly and that the
venting system is not blocked.
4. The control will then proceed through
a sequence of self-diagnostics before
initiating a trial for ignition.
5. During the trial for ignition, the pilot will
spark in an attempt to light the pilot. Once
the pilot flame is established, the main gas
valve will open allowing gas to flow to the
main burner.
6. The main burner and pilot will remain lit
throughout the heat cycle until the water
temperature setting is reached.
7. Once the water temperature setting is
reached, the control will close the main
gas valve and pilot valve which will
extinguish both the main burner and pilot
burner flames.
8. The blower motor will stay energized
for an additional 30 seconds after the
control verifies that the burner flame is
extinguished in order to clear combustion
gases from the water heater.
9. After the post-purge sequence, the control
will de-energize the blower motor and go
into a stand-by mode awaiting the next
call for heat.
This water heater is equipped with a
flammable vapor sensor that is monitored
continuously by the electronic control in all
modes of operation.
In the event that flammable vapors are
detected, the control will automatically shut
down the water heater and prevent the water
heater from being started again.
The following is a list of materials that will
cause the Flammable Vapor Sensor to shut
down the water heater.
 Vapors of Gasoline.
 Vapors of certain flammable paints, stains,
and thinners.
 Vapors of vent pipe Cement & Solvents.
 Bleach (direct contact with flammable vapor
sensor).
 Some other flammable materials and their
vapors.
If the flammable vapor sensor shuts down
the water heater, then the electronic control
will display the appropriate error code and
you should then promptly contact a qualified
service technician.
Refer to the “WARNING” on page 3 for
additional information.
Operating the water heater