?oleman FL8-UH Installation Instruction - Caution
035-17405-000 Rev. B (0801)
18
Unitary Products Group
If the actual input is not within 2% of the furnace rating, with
allowance being made for the permissible range of the regu-
lator setting (0.3 inches W.C.), replace the orifice spuds with
spuds of the proper size.
ADJUSTMENT OF MANIFOLD GAS PRESSURE
1.
Turn gas off at main gas valve. Remove 1/8" NPT plug
from the outlet pressure tap in the main gas valve body
and install proper manometer tube adapter fitting. Con-
nect line from gas valve tap to a manometer.
2.
Refer to Figure 14 on page17, for location of outlet
pressure tap and pressure regulator adjustment cap and
screw on main gas valve.
NOTE: The screw-off cap for the pressure regulator must be
removed entirely to gain access to the adjustment screw.
3.
Turn gas and electrical supplies ON. Turn gas valve
switch to ON position. Start furnace and observe mani-
fold pressure on manometer.
4.
Adjust manifold pressure by adjusting gas valve regula-
tor screw.
If gas valve regulator is turned in, or clockwise, manifold
pressure is increased. If screw is turned out, or counter clock-
wise, manifold pressure will decrease.
5.
Once the correct gas pressure to the burners has been
established, turn the gas valve switch to OFF and turn
the electrical supply switch OFF; then, remove the pres-
sure tap at the gas valve and re-install the plug using a
compound (on the threads) resistant to the action of LP
gases.
TABLE 5 : GAS RATE (CUBIC FEET PER HOUR)
SECO NDS
FO R
ON E
REVOLU TIO N
SIZ E
O F
TEST
DIAL
1/2
CUB IC
FO O T
1
CUBIC
FOO T
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
38
47
95
40
45
90
42
43
86
44
41
82
46
39
78
48
37
75
50
36
72
52
35
69
54
34
67
56
32
64
58
31
62
60
30
60
Be sure to relight any gas appliances that were
turned off at the start of this input check.
CAUTION
The cap must be replaced in order for the furnace
to operate properly.
MANIFOLD PRESSURE
NATURAL GAS
3.5” W.C.
PROPANE (LP) GAS
10.0” W.C.
The manifold pressure must be checked with the
screw-off cap in place on the pressure regulator.
If manifold pressure is too high, an over-fire condi-
tion exists which could cause heat exchanger fail-
ure. If the manifold pressure is too low, sooting
and eventual clogging of the heat exchanger could
occur.