Rheem TRITON Service And Training Manual page 23

Sequence of Operations
Pre-purge Cycle
If PS closes, then control board
initiates the pre-ignition cycle.
The pre ignition period verifies
the controllers gas valve relays
are open.
The word pre-purge will be in
the LCD display window.
Ignition Activation Period
The igniter sparks for 2 seconds.
During the trial for ignition, the gas
valve will open allowing gas to
enter the burner chamber.
The word Ignition will be in the
LCD display window.
Flame Rectification
The igniter is de-energized when
flame is sensed (8.0 micro amps).
If no flame is sensed within 3
seconds of the gas valve opening,
the trial for ignition period ends
and the unit recycles to a second
and / or third ignition attempt.
The control will monitor the flame
sense probe to confirm that a flame
is present.
Main Burner Operation
Once a flame is confirmed, the
control will enter the primary heating
mode.
The word Heating will be in the
LCD display window.
End of Heating Cycle
Once the set point is reached, the
gas valve is closed and the control
enters the post purge cycle.
Post Purge
The blower will run the post
purge cycle to purge the burner
and venting system of all
combustion gases. The word Post
Purge will be in the LCD display
window.
Pre-purge lasting 5 seconds will
check to make sure the venting is not
blocked and any unfavorable
combustion gases are expelled.
Gas valve relays are checked to make
sure they are open.
The spark ignition circuit is
activated.
Blower is operating and there is
power to the gas valve.
The control will execute an inter-
purge cycle if no flame is sensed.
The inter-purge cycle blows out
excess fuel from the combustion
chamber.
Once flame is rectified, the spark
igniter is de-activated.
Main burner is now in Heat Mode
and the controls heat the water in
the tank. It will continue heating
the water in the tank until the set
point temperature is reached.
Post purge expels latent heat and
combustion gasses.
When the post purge cycle is
complete, the blower is de-energized
and will stop.
2 3
Triton Service Manual SVC1020T ; Rev 4
80 and 100 gallon chassis
If controllers gas valve relay 1 is
not OPEN you will get an error
code of A036
If the proof of fan pressure switch
does not close, you will get an error
code A005, pre-purge and A004
during the heating cycle..
Main burner is on. There is no
pilot with this machine. It is a
Direct Spark Ignition (DSI)
burner.
If a flame is not verified within 4
seconds the gas valve will be
closed. If there is no proof of
flame after the three ignition
attempt cycles (total of 9
attempts), you will get an error
code of A01 Max Ignition
Attempts.
If flame exists for more than 4
seconds the retry counter is
zeroed.
The control enters normal
operating loop where all inputs are
continuously checked. Combustion
blower will accelerate to
maximum speed based on BTU
input.
If there is a presence of flame 10
seconds after the gas valve relays
close, you will get an error code of
A19 Flame Out To Late
If the proof of fan pressure switch
does not close, you will get an error
code A006, post purge.