440 04 6000 00
3
Specifications subject to change without notice.
START
−
UP, ADJUSTMENT, AND SAFETY
CHECK
General
1. Furnace must have a 115-v power supply properly
connected and grounded.
NOTE
: Proper polarity must be maintained for 115-v wiring.
Control status indicator light flashes rapidly and furnace
does not operate if polarity is incorrect or if the furnace is not
grounded.
2. Thermostat wire connections at terminals R, W, G,
and Y must be made at 24-v terminal block on
furnace control.
3. Natural gas service pressure must not exceed 0.5
psig (14- in. w.c., 1125 Pa), but must be no less than
0.16 psig (4.5-in. w.c., 350 Pa).
4. Blower door must be in place to complete 115-v elec-
trical circuit and supply power to the furnace
components.
UNIT OPERATION HAZARD
Failure to follow this caution may result in intermittent
unit operation or performance satisfaction.
These furnaces are equipped with a manual reset limit
switch in burner assembly. This switch opens and
shuts off power to the gas valve if an overheat
condition (flame rollout) occurs in the burner
assembly/enclosure. Correct inadequate
combustion
−
air supply, improper gas pressure setting,
improper burner or gas orifice positioning, or improper
venting condition before resetting switch. DO NOT
jumper this switch.
CAUTION
!
Before operating furnace, check flame rollout manual reset
switch for continuity. If necessary, press button to reset
switch.
EAC-1 (115vac) terminal is energized whenever blower
operates. HUM (24vac) terminal is only energized when the
low pressure switch (LPS) is closed on a call for heat.
Prime Condensate Trap with Water
CARBON MONOXIDE POISONING HAZARD
Failure to follow these warnings could result in personal
injury or death.
Failure to use a properly configured trap or NOT
water-priming trap before operating furnace may allow
positive pressure vent gases to enter the structure
through drain tube. Vent gases contain carbon
monoxide which is tasteless and odorless.
!
WARNING
1. Remove upper and middle collector box drain plugs
opposite of the condensate trap. (See Figure 10.)
2. Connect field-supplied 5/8-in. (16 mm) ID tube with at-
tached funnel (see Figure 10) to upper collector box
drain connection.
3. Pour one quart (liter) of water into funnel/tube. Water
should run through collector box, overfill condensate
trap, and flow into open field drain.
4. Remove funnel; replace collector box drain plug.
5. Connect field-supplied 5/8-in. (16 mm) ID tube to
middle collector box drain port.
6. Pour one quart (liter) of water into funnel/tube. Water
should run through collector box, overfill condensate
trap, and flow into open field drain.
7. Remove funnel and tube from collector box and
replace collector box drain plug.
Purge Gas Lines
If not previously done, purge the lines after all connections
have been made and check for leaks.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber.
Never test for gas leaks with an open flame. Use a
commercially available soap solution made
specifically for the detection of leaks to check all
connections. A fire or explosion may result causing
property damage, personal injury or loss of life.
!
WARNING
Adjustments
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
DO NOT bottom out gas valve regulator adjusting
screw. This can result in unregulated manifold
pressure and result in excess overfire and heat
exchanger failures.
!
WARNING
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in reduced
furnace life.
DO NOT redrill orifices. Improper drilling (burrs,
out
−
of
−
round holes, etc.) can cause excessive burner
noise and misdirection of burner flames. This can
result in flame impingement of heat exchangers,
causing failures. (See Figure 1.)
CAUTION
!
BURNER
ORIFICE
A93059
Figure 1
−
Orifice Hole
For proper operation and long term reliability the furnace
input rate must be /
−
2 percent of input rate on
furnace rating plate, or as adjusted for altitude.
