441 01 2314 06
Specifications are subject to change without notice.
26
NOTE: It is very important to reinstall the NOx insert mounting
screws.
Figure 22
Removing NOx inserts
Representative drawing only, some models may vary in appearance.
Main Burner Flame Check
Allow the furnace to run approximately 10 minutes. Then inspect
the main burner and pilot flames. See
Figure 23
.
Check for the following (
Figure 23
):
•
Stable and blue flames. Dust may cause orange tips or wisps
of yellow, but flames
MUST NOT
have solid, yellow tips.
•
Flames extending directly from burner into heat exchanger.
•
Flames do
NOT
touch sides of heat exchanger
If any problems with main burner flames are noted, it may be nec-
essary to adjust manifold gas pressure, or check for drafts.
Main Burner
Burner Face
10
−
10
−
78
Figure 23
NOTE: For Ignitor location see
Figure 24.
Ignitor Location
in (mm)
Figure 24
5
/
16
(8)
1
/
4
(6.4)
2
1/
16
(52.4)
25-25-08
NOTE:
Flame sensor has a different orientation in all 050 models.
Air Temperature Rise Check
!
REDUCED FURNACE LIFE HAZARD
Failure to follow this caution may result in reduced
furnace life.
Use
ONLY
the blower motor speed taps insert
indicated in the
Circulation Air Blower Data
for
setting air temperature rise.
CAUTION
The blower speed
MUST
be set to give the correct air temperature
rise through the furnace as marked on the rating plate. Tempera-
ture rise is the difference between supply and return air tempera-
tures.
To check temperature rise, use the following procedure:
1. Place thermometers in supply and return air registers as close
to furnace as possible, avoiding direct radiant heat from heat
exchangers.
2. Operate furnace for 10 minutes with all the registers and duct
dampers open by using a jumper wire on R to W thermostat
connections on the control board.
3. Take readings and compare with range specified on rating
plate.
4. If the air temperature rise is not in the correct range, the blow-
er speed must be changed. A higher blower speed will lower
the temperature rise. A lower blower speed will increase the
temperature rise.
5. Remove the jumper wire after the adjustments are complete.
Changing Blower Speed
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in
personal injury or death.
Turn OFF power to furnace, lockout and tag with a
suitable warning label, before changing speed
taps.
!
WARNING
NOTE
: The speed taps that the manufacturer sets at the factory
for this furnace are based on a nominal 400 CFM per ton cooling
and the basic mid range on the temperature rise for heating.
Since the manufacturer cannot predict the static pressure
that will be applied to the furnace, it is the responsibility of the
installer dealer/contractor to select the proper speed tap
leads for the application when the furnace is installed.
If it is necessary to change speeds, refer to steps below.
1. Refer to
Furnace Wiring Diagram
for location of the heating
and cooling speed taps located on the furnace control as well
as location of unused blower motor speed leads. Use the
chart (
Table 7
) to determine the blower motor speed settings.
Table 7
Blower Speed Chart
Wire Color
Motor Speed
Black
High
Orange
*
Med
−
High
Blue
Med
−
Low
Red
Low
*
Med
−
High speed may not be provided on all models.
