650.65-N2
Turn the electrical and gas supplies back on, and with the
burners in operation, check for gas leakage around the plug
with a soap and water solution.
ADJUSTMENT
OF
PRIMARY AIR
The main burners should be in operation for 15 minutes before
making the primary air adjustment. The burner flame should
not contain any yellow color (Refer to Figure 13). With the
furnace operating al full input, adjust the primary·air of the
burners as follows:
COMBUSTION AIR INTAKE
BURNER
BURNER
FLAME
RGURE
1 3-
PROPER FLAME APPEARANCE
CAUTION:
The front panel of the burner enclosure must
be
in
place and secured with screws during normal operation
and when observing the proper burner flame.
Natural Gas or Propane (LP)
All models are shipped with the air shutters wide open. Local
variations in the gas supply may require changes in the settings
described above. To change the air shutter settings, use the
following procedure:
1.
Remove the front access door.·
2.
Turn off all power to the unit and remove the front door of
the burner box.
3. Rotate the burners until the air �hutter locking screw is
facing downward.
4.
Adjust the air shutters with the power to the unit "OFF" and
retighten the locking screws.
5. Re-install the front door of the burner
box
and tighten the
screws which secure the door.
6.
Restore power and start the unit. Observe through the
observation port to see if all flames are now blue in color.
If yellow flames are still visible, repeat steps
2
thru
6.
7. Cycle the burners on an off a few times to verify the burners
are lighting promptly and properly
8.
Replace front access door.
CHECKING GAS INP U T (NATURAL GAS)
NOTE:
Front door of burner box must
be
secured when check
ing gas input.
1.
T urn off all other gas appliances connected to the gas
meter.
2.
With the furnace turned on, measure the time needed for
one revolution of the hand on the smallest dial on the
meter. A typical domestic gas meter usually has a
1/2
or
1
cubic foot test dial.
3.
Using the number of seconds for each revolution and the
size of the test dial increment, find the cubic feet of gas
'
•
t
,.-_
I"")
TABLE 3
GAS RATE (CUBIC FEET PER HOUR)
Seconds for
Size of Test Dial
one RevoL
1/2
cu.
ft.
1
cu.
ft.
10
180
360
12
150
300
14
129
257
16
113
225
18
100
200
20
90
180
22
82
164
24
75
150
26
69
138
28
64
129
30
60
120
32
56
113
34
53
106
36
50
100
47
95
40
45
90
42
43
44
4 1
82
46
39
78
37
75
50
36
72
52
35
69
54
34
67
56
32
64
58
3 1
6 2
60
-
30
60
NOTE:
To find the Btuh input, multiply the number of cubic feet
of gas consumed per hour by the BTU content of the gas
in your particular locality. Contact your gas company for
this information, as it varies widely from city to city.
EXAMPLE: It is found by measurement that it takes
26
seconds
for the hand on the
1
cubic foot dial to make a revolution with
only a
120,000
Btuh furnace running. Using this information
locate
26
seconds in the first column of Table
3.
Read acros
�
to the column headed
"1
cubic foot• where you will see that
138
cubic feet of gas per hour are consumed by the furnace at that
rate. Multiply 138 by
850
(the BTU rating of the gas obtained
from the local gas company). T he result is 117,300 Btuh, which
is close to the
120,000
Btuh rating of the furnace.
If the actual input is not within
5%
of the furnace rating, with
allowance
be
in§ made for the permissible range-of the regula·
tor setting ( 0.3 inches W.C.), replace the orifice spuds with
spuds of the proper size.
CAUTION:
Be sure to relight any gas appliances that were
tumed off at the start of this input check.
ADJUSTMENT
OF
TEMPERATURE RISE
The temperature rise, or temperature difference between the
return air and the heated air from the furnace, must
be
within
the range shown on the furnace rating plate and within the
application limitations shown in Table 1. After the temperature
rise has been determined, the cfm can be calculated.
After about
20
minutes of operation, determine the furnace
temperature rise. Take readings of both the return air and the
h�"'"rl
in thr> rl• wt� :::.hrHit �i""
IPP.I
from th� fumac�
where
