Coleman 035-16329-002 Owner's Manual page 5

035-16329-002 Rev. B (0304)
2. When the furnace control
board is activated, the combus-
tion air blower is turned on.
3. As the combustion air blower
increases in speed, the con-
tacts of the pressure switchwill
close and complete the electd-
cal circuit to the ignitioncircuit.
4. During the next 40 to 50 sec-
onds, the combustion air
blower will bringfresh air into
the heat exchanger and the
ignitorwill begin to glow. At the
end of this pedod, the gas
valve wi!l open and the burner
will light.
5. After the burner lights, a sepa-
rate sensor acts as a flame
probe to check for the pres-
ence of flame. As long as flame
is present, the system will
monitor it and hold the gas
valve open.
6. If the burner fails to light within
6-8 seconds after the gas valve
opens, the gas valve will close
and the ignitor will be turned
off. After a short pause, the
system will recycle and try
again for ignition. If the burner
fails to light atler three tdes, the
ignition system will lock out.
The system will remain in lock-
out mode for a period of one
hour, then the furnace will try
for ignition again.
7. The lapsed time from the
moment the room thermostat
closes to when the burner
lights may be 45-60 seconds.
This delay is caused by:
a. The time required for the
ignitorto heat up and
b. The time required for fresh
air to be brought into the
heat exchanger.
8. Approximately 60-90 seconds
after the burner lights,furnace
air circulationblower will run.
9. When roomthermostat is setis-
fled, the circuit to the furnace
control board is opened. The
circuitto the combustion air
blower and the gas valve is
opened and the burner is extin-
guished. Then the furnace con-
trol board will keep the
circulatingblower running for a
fixed pedod of time to allow
additionalheat to be drawn
from the heat exchanger.
DIAGNOSTIC LIGHT
If furnace does not maintain home
temperature as set, check the light
indicator, visible through a small
window in the dght side of the fur-
Race controlbox.
The electronic furnace control is
equipped with a diagnostic light
which flashes when there is a ser-
vice problem. The diagnosticcodes
are;
Steady on: Normal operation.
ONE flash: Ignition failure.
TWO flashes: Pressure switch
failed closed.
THREE flashes: Pressure switch
failed open.
FOUR flashes: Limitswitch open.
FIVE flashes: Gas valve energized
with no call for heat
SIX flashes or
rapid flash: Reversed poladty
If a problem is indicated, contact
your authorized service person.
THE FURNACE CONTROLS
AND THEIR FUNCTION
1. System Switch - This system
switch turns =ON" or "OFF" the
120 volt electdcal circuitthat
powers the furnace controls
and the blower motor. The sys-
tem switch must be turned
"ON" for the furnace to oper-
ate. Turn the switchto "OFF"
when cleaning the blower,etc.
2. Limit Control - This furnace is
protected by two (2) high tam-
perature limitswitches.The
lower limitswitch is an auto-
matic reset type.
3. Gas Valve - The gas valve for
the gas furnaces are a 100%
shut-offtype and willfail safe if
for some reason the gas is
turned off.
Unitary Products Group 5