Rheem RRPL-B Installation Instructions Manual page 29

NORMAL HEAT MODE
A. Call For First Stage (low fire) Only:
1. Zone thermostat contacts close, a call for first stage (low fire) heat is initiated.
2. Control runs self check.
3. Control checks the high-limit switch for normally closed contacts, each pressure switch
for normally open contacts, and all flame rollout switches for continuity.
4. Control energizes high inducer speed.
5. Control checks pressure switches for closure.
6. If pressure switches are closed, the control starts a 30 second prepurge.
7. After prepurge timeout, control initiates spark for 2 seconds minimum, 7 second maxi-
mum ignition trial, initiates 30 second, second stage (high fire) warm up timing.
8. Control detects flame, de-energizes spark and initiates 30 second delay on blower tim-
ing.
9. After a fixed 30 seconds indoor blower delay on, the control energizes the indoor blow-
er.
10. After the 30 second second stage warmup period control checks thermostat input. If
only W1 is called for, W2 is de-energized and the control starts a 5 second off delay on
the W2 inducer speed.
11. After fixed 5 seconds the gas valve shifts to low and the W2 inducer speed is de-ener-
gized.
12. Control enters normal operating loop where all inputs are continuously checked.
B. Call For Second Stage, After First
Stage Established; Starting from A.11:
1. If a call for second stage (high fire) is initiated after a call for first stage heat is estab-
lished, the control energizes the W2 inducer speed assures the high-fire pressure
switch is closed and energizes the second stage of the gas valve.
2. Control enters normal operating loop where all inputs are continuously checked.
C. Second Stage Satisfied; First Stage
Still Called For; Starting From B.2:
1. Once the call for second stage is satisfied, the control starts a 30 second off delay on
W2 inducer and reduces the gas valve to first stage.
2. Control enters normal operating loop where all inputs are continuously checked.
D. First Stage Satisfied:
1. Zone thermostat is satisfied.
2. Control de-energizes gas valve.
3. Control senses loss of flame.
4. Control initiates 5 second inducer postpurge and 90 second indoor blower delay off.
5. Control de-energizes inducer blower.
6. Control de-energizes indoor blower.
7. Control in the stand by mode with solid red LED.
E. First Stage and Second Stage
Removed Simultaneously:
1. Upon a loss of W1 and W2 the gas valve is de-energized.
2. Upon a loss of flame, the inducer will complete a 5 second postpurge and the indoor
blower will complete a 90 second delay off.
3. Control in the stand by mode with solid red LED.
The integrated control is a four-ignition system.
After a total of four cycles without sensing main burner flame, the system goes into a 100%
lockout mode. After one hour, the ignition control repeats the prepurge and ignition cycles
for 4 tries and then go into 100% lockout mode again. It continues this sequence of cycles
and lockout each hour until ignition is successful or power is interrupted. During the lockout
mode, neither the ignitor or gas valve will be energized until the system is reset by turning
the thermostat to the "OFF" position or interrupting the electrical power to the unit for 3
seconds or longer. The induced draft blower and main burner will shut off when the ther-
mostat is satisfied.
The circulating air blower will start and run on the heating speed if the thermostat fan
switch is in the "ON" position.
The integrated furnace control is equipped with diagnostic LED. The LED is lit continuously
when there is power to the control, with or without a call for heat. If the LED is not lit, there
is either no power to the control or there is an internal component failure within the control,
and the control should be replaced.
If the control detects the following failures, the LED will flash on for approximately 1/4 sec-
ond, then off for 3/4 second for designated failure detections.
1 Flash: Failed to detect flame within the four tries for ignition.
2 Flash: Pressure switch or induced draft blower problem detected.
3 Flash: High limit or auxiliary limit open.
4 Flash: Flame sensed and gas valve not energized or flame sensed with no "W" signal.
5 Flash: Overtemperature switch open.
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