Sequence Of Operations - Rheem TRITON Service And Training Manual

Sequence of Operations

Upon application of power, the controls performs an internal check, retrieves and inspects relevant
data from Electrically Erasable Programmable and Read Only Memory (EEPROM), and analyzes the
120 VAC power line for polarity and ground connections. After the control performs selected system
diagnostic checks and if all checks are successfully passed, the control measures water temperature.
Whenever the water temperature is less than the set point minus the differential, an internal call for
heat is generated. The burner is then allowed to run until the "call for heat" is removed when the
water temperature is equal to or greater than the set point.
Power ON
When the control is powered, it
should display the Rheem heater
model, water temperature,
operating setting temperature and
heater status. (If temp is above
120°, a scald warning will
appear)
If the control determines that the
actual water temperature inside the
tank is below the programmed
temperature set point minus the
differential, a call for heat is
activated
Call for Heat
On a call for heat, the
microprocessor runs its self-check
routine and clears the retry
counters. The control then
performs selected system
diagnostic checks. This includes
confirming the proper state of the
pressure switches, exhaust flue
temperature, water temperature
sensors and ECO high limit
device.
The system will energize the
blower once the pressure switch is
detected open. If all checks are
successfully passed; the
combustion blower is energized
for the pre-purge cycle.
Water temperature thermistor
(thermostat) measures the water
temperature inside the tank.
Checks to make sure the ECO is
not tripped.
Checks to make sure that flue gas
temperature is less than 190°F
(normal state).
Checks to make sure the pressure
switch (proof of fan) is OPEN
(normal state) prior to activating
blower.
Blower will operate at ignition
speed for up to 30 seconds to close
the Proof of Fan switch.
22
Triton Service Manual SVC1020T ; Rev 4
80 and 100 gallon chassis
.
The control will not initiate a call
for heat while in any lockout
condition.
Resolve any error codes in the
LCD display.
Check that the ECO is not open;
verify water temperature is below
0
200 F. If the ECO is tripped, you
will get an error code of A016.
Check flue gas sensor. Resistance
reading should be within the range
in Chart on page 21. If the flue gas
temperature exceeds 155°F, the
controller will indicate an error
code of A017
Check Proof of Fan pressure
switch. Continuity indicates a
closed or damaged switch. If POF
switch is closed before activation
of the blower, you will get an error
code of A008.
If Proof of Fan switch is open, pre-
purge continues while control board
checks if pressure switch closes. If
POF switch is not open, you will get
an error code of A008.