Thermo Pride Gas/Propane Furnace Premiere Series 2-Stage CHX3 - Manual (Page 41)

All installations and services must be performed by qualified service personnel.
35
CONTINUOUS SAFE OPERATION CHECK
IF FLAME SIMULATION CONDITION PRESENT OR ROLL-OUT SWITCH
OPENS, SYSTEM ENERGIZES INDUCER FAN FOR 15 SECONDS AND
CIRCULATOR BLOWER AT HEATING SPEED UNTIL SITUATION CORRECTION
AT ANY TIME THE
GAS VALVE IS
NOT ENERGIZED
A. SEQUENCE OF OPERATIONS
THERMOSTAT CALLS FOR
HEAT W1 OR W1 & W2,
CONTACTS CLOSE
LOW FIRE PRESSURE
SWITCHES SENSES ADEQUATE
DIFFERENTIAL PRESSURE,
CONTACTS CLOSE
IV. STARTING THE UNIT
INDUCER REDUCES
TO LOW SPEED
LOW PRESSURE SWITCH
SENSES ADEQUATE
PRESSURE DIFFERENTIAL,
CONTACTS STAY CLOSED
50V51-843 CONTROL
ENERGIZED, INDUCER
ENERGIZED ON HIGH SPEED
PREPURGE IGNITION DELAY,
INDUCER RUNS FOR 15 SECONDS
POWER IS APPLIED TO
THE WHITE RODGERS
SILICON NITRIDE IGNITOR.
IGNITOR WARM-UP IS
17 SECONDS