Table 2 Gas Pressures -in wc (Pa)
Gas SupplyPressure
Type Recommended Max. Min.
7 in wc 14in wc 4.5 in wc
Natural (1744Pa) (3487Pa) (1121Pa)
*See Table 1
Important Notes
Manifold
Pressure
3.5*
(872 Pa)
Measured input can NOT exceed rated input.
Any major change in gas flow requires changing burner
orifice size.
Start-up and Check-out
1. Remove the plug from the Inlet Pressure Tap on gas valve and
install a manometer. (See Figure 5)
2. Open manual gas line valve to unit. Check for gas leaks and
correct as necessary. Check supply pressure, 7 in wc (1744Pa)
recommended, 4.5 in wc (1121Pa)minimum, 14 in wc (3487 Pa)
maximum. If not within these limitations DO NOT OPERATE
FURNACE, contact gas supplier.
3. Close manual gas line valve to unit, remove manometer and re-
place inlet pressure tap plug.
Gas Valve Adjustment
1. With the gas valve knob or switch in the OFF position, remove
the pressure tap plug from the outlet end of the valve, and con-
nect a "U" tube manometer to the pressure port. (Figure 5)
2. Turn the gas valve knob or switch to the ON position and restore
electrical power to unit. Cycle the main burner on and off sever-
al times to stabilize the pressure regulator diaphragm. This
MUST be done before an accurate pressure reading can be ob-
tained.
3. With the main burner on, read the manometer. For appropriate
reading see Table 1. Turn pressure regulator adjusting screw
clockwise to increase or counterclockwise to decrease man-
ifold pressure. Burner Input must not exceed nameplate rating.
Refer to Section "Checking Input Rate".
4. Turn gas valve to OFF. Remove the manometer and replace the
pressure tap plug and pressure regulator cap screw.
5. Start the main burners and check pressure tap plug for gas
leaks.
6. With gas valve on, observe furnace through two or more com-
plete cycles to be sure all controls are operating.
Checking Input Rate
Checking Burner Input Using A Meter To check the BTU inputrate,
the test hand on the meter should be timed for at least one revolution
and the input determined from this timing. Refer to Section 11, Table
I1.1.1of the National Fuel Gas Code for converting test hand readings
to cubic feet per hour.
Example (BTUH)
NaturalGas No.of Time Per BTU Per
BTU Contentper Seconds Cubic Foot in
cu.foot Per Hour Seconds Hour
1,000 3,600 48 75,000
1,000x 3,600+ 48 =75,000 BTUH
To Determine the appliance kW input rate from a .05m 3test dial that
has been clocked at 80 seconds for one complete revolution.
Example (kW)
Number of
Number of
seconds per seconds per Sizeof test dial
hour complete (.05m3) kW m3/h
rotation
3,600 80 .05 2.25
3,600+ 80x .05 = 7.2 m3/h
2.25m3/hx 10.35 kWh/m3=23.28 kW
23.28 x 3.412 =79,431 BTU
*High Altitude Input Rate =
Nameplate Sea Level Input Rate x (Multiplier)
HighAltitude
Elevation Multiplier
NaturalGas*StandardInput
1.00
0.95
0.93
0.91
0.89
0.87
0.85
0'- 2000' (0 - 609.6)
2001' - 3000" (609.9 - 914.4)1-
3001' - 4000" (914.7 - 1219.2)
4001' - 5000" (1219.5 - 1524)
5001' - 6000" (1524.3 - 1828.8)
6001' - 7000" (1829.1 - 2133.6)
7001' - 8000" (2133.9 - 2438.4)
*Based on mid-range of elevation.
In the USA, derating of these furnaces at 2% (Natural Gas) and
4% (Propane Gas) has been tested and design-certified by
CSA.
1- In Canada, the input rating must be derated 5% (Natural Gas)
and 10% (Propane Gas) for altitudes of 2,000 to 4,500 (609.6
to1371.6m) above sea level. Use the 2001 to 3000 (609.9 to
914.4m) column in Table 1.
Main Burner Flame Check
Allow the furnace to run approximately 10 minutes then inspect the
main burner and pilot flames. Check for the following: (See Figure 7)
• 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 neces-
sary to adjust gas pressures or check for drafts.
Figure 7 J Main Burner
Burner
10-10-78
High Altitude Derated Unit Label
The derated label supplied with the conversion kit must be completed
and affixed to the furnace near the rating plate. Fill in the manifold
pressure, orifice size and revised input rate.
Refer toTable 1 provided to determine the proper orifice part numbers
for ordering purposes.
Verify System Operation
Upon completion of all conversion procedures, perform the following
steps to attach appropriate labels and verify the system operation.
1. Locate the Natural Gas Conversion Label next to the furnace
rating plate. Replace Propane Gas Conversion Label ifthere.
2. Fill out and attach the Field Conversion Label to the front exteri-
or of the furnace. Replace any existing Field Conversion Label.
3. Turn the thermostat to itslowest temperature setting or to OFF if
equipped with a System Select Switch.
4. Turn the gas valve control knob or switch to ON.
5. Reinstall all access panels.
6. Turn ON all electrical power to the unit.
7. Set the thermostat to the desired temperature and the System
Select Switch to HEAT.
8. Observe unit operation through two complete heating cycles. See
"Sequence of Operation" in furnace installation instructions.
International Comfort Products, LLC
Lewisburg, TN 37091 U.S.A.
44106108300 Specifications subject to change without notice. 4
