Use & Care Manual

Sequence of Operation
During initial start-up or a call for heat, the con-
trol will verify the vacuum switch is open.
Once the control verifies the vent pressure switch
is open, the control will energize the blower
motor for the pre-purge sequence (approximately
5 seconds).
The control will verify that the vent pressure
switch has closed, ensuring that the blower is
functioning properly and that the venting system
is not blocked.
The control will then proceed through a sequence
of self-diagnostics before initiating a trial for igni-
tion.
During the trial for ignition, the hot surface ignit-
or will warm up.
Once the hot surface ignitor warms up, the main
gas valve will open allowing gas to flow to the
main burner.
Once the main burner ignites, the control will
verify that the burner flame is present through the
flame sense circuit. The hot surface ignitor will
then turn off.
The main burner will remain lit throughout the
heat cycle until the water temperature setting is
reached.
Once the water temperature setting is reached, the
control will close the main gas valve which will
extinguish the main burner flames.
The blower motor will stay energized for an
additional 5 seconds after the control verifies that
the burner flame is extinguished in order to clear
combustion gases from the water heater.
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 dis-
play the appropriate error code and you should
then promptly contact a qualified service techni-
cian.
Refer to the “NOTICE” on page 3 for additional
information.
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