CONQUEST 80 - Service Analyzer Charts; Remote Flame Sensor

SERVICEANALYZERCHARTS
Symptoms
1.
► Igniter won't heat (HSI)
or spark (DSI)
2. Remote flame sensor does
not sense flame
3. Igniter does not sense flame
4.
Pilot does not stay lit
5. Excessive burner cycling
6.
Temperature overrides
Possible Cause
Broken or cracked carbide tip
Frayed or damaged leads or plugs
Replace igniter
No 120-volt ac to igniter Check wiring; perform integrated
furnace control test, and replace
as necessary
Pressure switch open
Polarity of line power reversed
Improper flame
Sensor out of position
Sensor contaminated
Igniter contaminated
Gas pressure too high
Failed thermocouple
Unstable pilot flame
Failing pilot valve
Inadequate combustion air
Downdrafts in vent pipe
Improper pilot orifice positioning
Pilot hood below flame runner
Failed pilot assembly
Pilot draft hood bent or out of position
Dirty filters
Limit control cycling
Insufficient return air or
low airflow
Thermostat incorrectly installed
Incompatible thermostat (example:
some night set back thermostats)
Thermostat failed, improper
anticipator setting
Thermostat heat anticipator
set too high
Thermostat needs calibrating
Check/Remedies
•
Replace igniter
Refer to "Pressure Switch"
check out ( #21 )
Check polarity and correct or
complete integrated furnace
control test
Check/reset gas pressure
Adjust bracket
Clean with steel wool
and recheck
Add Remote Flame Sensor,
AS-58494-01
Check/reduce gas pressure
Replace thermocouple
Adjust gas valve pilot screw
Replace gas valve
Provide more combustion air
Correct venting, add diffuser plate
Correct orifice positioning
Reposition pilot hood above
•
flame runner
Replace with Pilot Assembly
Kit 62-22864-82
Replace pilot assembly
Clean or replace
Check for control fault
Check temperature rise
through unit; check fan speed
Check location for possible
drafts; check anticipator setting
Change thermostat or use
isolation relay
Replace; check current and set
heat anticipator accordingly; or,
add 100 ohm resistor across
terminals "W" and "C" on furnace
control board
Thermostat heat anticipator
setting should be total control
ampere load or may require
addition of 100 ohm, 10 watt
resistor across terminals
"W" and
"C" on furnace control board
Calibrate per instructions or
level subbase
•
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