Instructions / Assembly

31
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 vapors
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.