18-CD30D1-12
47
Installer’s Guide
CORRECT METHOD OF CHECKING DIRECT VENT MANIFOLD PRESSURE
WITH BURNER BOX REFERENCED
I
Manifold
Pressure
Measurement
Fitting
Field Supplied
Connects to
Burner Box
Pressure Hose
A Field Supplied barb fitting must be used
on the gas valve to attach the hose
Gas Valve
On/ Off
Toggle
Switch
High Heat
Manifold
Pressure
(Adjustment
under cover)
Inlet Pressure
Measurement Fitting
O
Negative Control
Pressure Post
Positive Control
Pressure Post
Low Heat Manifold
Pressure
(Adjustment under
cover)
Manifold
Pressure
Measurement
Fitting
Flow
TABLE 21
Furnace Input
rate (KBTU/hr)
FINAL LP MANIFOLD PRESSURE SETTINGS
(inches w.c.)
40%
65%
100%
60
2.1 ± 0.5
Not Adjustable
10.0 ± 0.5
80
2.1 ± 0.5
Not Adjustable
10.0 ± 0.5
100
2.1 ± 0.5
Not Adjustable
10.0 ± 0.5
Downflow 120
2.1 ± 0.5
Not Adjustable
10.0 ± 0.5
Upflow 120
2.9 ± 0.5
Not Adjustable
10.0 ± 0.5
For upflow 120KBTU/hr model, 1st stage is 45%
Manifold pressures apply for Propane applications ONLY
Furnace Input
rate (KBTU/hr)
FINAL NG MANIFOLD PRESSURE SETTINGS
(inches w.c.)
40%
65%
100%
60
0.7 + 0.2 / - 0.0
Not Adjustable
3.5 ± 0.2
80
0.7 + 0.2 / - 0.0
Not Adjustable
3.5 ± 0.2
100
0.7 + 0.2 / - 0.0
Not Adjustable
3.5 ± 0.2
Downflow 120
0.7 + 0.2 / - 0.0
Not Adjustable
3.5 ± 0.2
Upflow 120
0.9 + 0.2 / - 0.0
Not Adjustable
3.5 ± 0.2
For upflow 120KBTU/hr model, 1st stage is 45%
Manifold pressures apply for Natural Gas applications ONLY
▲
WARNING
!
EXPLOSION HAZARD
REPLACE AND/OR TIGHTEN
ALL PLUGS REMOVED
OR LOOSENED WHEN
ADJUSTING GAS PRESSURE.
LEAK CHECK THE FITTINGS
BEFORE PLACING INTO
REGULAR SERVICE.
FAILURE TO FOLLOW THIS
WARNING COULD RESULT IN
SERIOUS PERSONAL INJURY,
PROPERTY DAMAGE, OR
DEATH
Slope
Gauge
