LENNOX Furnace/Heater, Gas Manual L0806918

User Manual: LENNOX LENNOX Furnace/Heater, Gas Manual LENNOX Furnace/Heater, Gas Owner's Manual, LENNOX Furnace/Heater, Gas installation guides

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ZENNDX
2003 Lennox Industries Inc.
Dalias, Texas, USA
GAS KITS & ACCESSORIES
504,659M
6/2003 HIGH ALTITUDE KIT
I
INSTALLATION INSTRUCTIONS FOR HIGH ALTITUDE KIT (47M82) USED WITH
ALL G40UH, G41UF, G50UH & G50UHi UNITS & G51MP-135 UNITS FUELED BY NATURAL GAS
WARNING
,CAUTION
Package 1 of I contains the following:
7 - Main burner orifices (0.081)
1 - Gas converter sticker
1 - Nameplate conversion sticker
High altitude kit (47M82) is used to convert all G40UH,
G41UF, G50UH and G50UHi units and G51MP-135
units which are fueled by natural gas for operation at
altitudes from 7501 to 10,000 ft. (2287 to 3048 m).Units
installed in these high altitude applications also require
installation of a replacement pressure switch, which is
ordered separately. Refer to table 1 for pressure switch
requirements.
TABLE 1
Pressure Switch Requirements
Model Number
Altitude
750140,000 ft.
(2287 - 3048 m)
Pressure
Switch
G40UH/G50UH(i)=045 56L32
G40UH/G50UH(i)=070
G40UH/G50UH(i)-090
G40UH/G50UH(i)=110 15M22
G40UH/G50UH(i)q 35
G40UH/G50UH(i)q 55
G41UF=045
G41UF=070 46M94
G41UF=090
G41UF-110
G41UF-135 46M95
G51MP=135 56M06
NOTE -Pressure switch is factory set. No adjustment necessary.
06/03
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Page 1
1 - Set the thermostat to the lowest setting. Shut off the
gas supply to the furnace, then disconnect the
electrical power.
2 - Remove the heating compartment access panel and
burner box cover, if necessary. Turn the automatic
gas valve knob, or switch the gas valve lever, to the
OFF position. See figures 3, 4,5 and 6.
3 - Disconnect the gas supply from the gas valve. Mark
the wires for identification and disconnect the wiring
at the gas valve.
4 - Remove the four manifold securing screws. Remove
the manifold/gas valve assembly. Replace the main
burner orifices with the provided orifices (.081). See
figure 1.
5 - Re-install the manifold/valve assembly. Reconnect
wiring to the gas valve.
MANIFOLD/GAS VALVE ASSEMBLY REMOVAL
(G41UF Unit Shown)
ORIFICES BURNERS
MANIFOLD /GAS
VALVE
ASSEMBLY
FIGURE 1
504,659M
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Pressure Switch Replacement
G40UH and
GSOUH(i) Units
GASKET
COLLECTOR
BOX
TUBING
GASKET_ COMBUSTION
AIR ORIFICE
PRESSURE
SWITCH
COMBUSTION
AIR INDUCER
G41UF Units
PRESSURE
SWITCH
TUBING
COLLECTOR
BOX
COMBUSTION
AIRINDUCER
G51MP-135
PRESSURE
SWITCH \
COLLECTOR
BOX
/
/
/
/
TUBING
COMBUSTION _
AIR INDUCER PRESSURE
SWITCH TUBING
FIGURE 2
6 - All units installed at altitudes above 7,500 ft. (2286m)
require a replacement pressure switch assembly.
See table 1 for the proper switch assembly. Refer to
figure 2 for pressure switch location.
a - Remove the tubing from the barbed fitting on the
pressure switch(es)
b - Remove screw(s) which secure pressure switch
assembly(ies). Install replacement pressure
switch(es) using existing screw(s).
c- Securely attach flexible tubing to fitting on
replacement pressure switch assembly(ies).
See figure 2.
AWARNING
7 - Reconnect the gas supply to the manifold and turn on
gas supply to unit.
AIMPORTANT
CAUTION
8 - Replace burner box cover, if necessary.
9 - Restore the electical power to the unit,
10-Affix nameplate conversion sticker next to unit
nameplate,
11 - Complete the information required on the converter
sticker: date, name, and address. Affix sticker to the
exterior of the unit in a visible area.
12 - Follow the steps given in the start-up and adjustment
section.
13 - Energize the thermostat several times to ensure the
ignition control is operating and that the SureLight ®
ignitor glows.
14 - Replace the heating compartment access panel.
Page 2
BEFORELIGHTING- Smellall around the appliance
area for gas. Be sure to smell next to the floor because
some gas is heavier than air and will settle on the floor.
Use only your hand to turn the gas control knob or the
control lever. Never use tools. If the knob or lever will not
turn by hand, do not try to repair it. Call a qualified service
technician. Force or attempted repair may result in a fire
or explosion.
A- Placing the Unit into Operation
AIMPORTANT
G40UH, G41UF, G50UH(i) and G51MP series units are
equipped with a Surelight ® ignition system. The
Surelight ¢ ignition system automatically lights the
burners each time the thermostat calls for heat.
1 - STOP] Read the safety information at the beginning
of this section.
2 - Set the thermostat to its lowest setting.
3 - Turn offall electrical power to the furnace.
4 - Do not try to light the burners by hand.
5 - Remove the unit access panel.
6 - Turn the knob on the gas valve clockwise _' (or
move the lever) to the OFF position. Do not force.
See figures 3, 4, 5 and 6.
7 - Wait five (5) minutes for any gas to clear out. If you
then smell gas, STOP? Immediately call your gas
supplier from a neighbor's phone. Follow the gas
supplier's instructions. If you do not smell gas, go to
the next step.
8 - Turn the knob on the gas valve counterclockwise
(or move the lever) to the ON position.
Honeywell VR8205 Series Gas Valve
REGULATOR
ADJUSTMENT
INLET T_
PRESSURE
GAS VALVE SHOWN IN OFF POSITION
FIGURE 3
White Rodgers 36E Series Gas Valve
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW
INLET
PRESSURE
TAP
OUTLET
PRESSURE
TAP
GAS VALVE SHOWN IN OFF POSITION
FIGURE 4
White Rodgers 36F Series Gas Valve
INLET
PRESSURE
TAP
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW
OUTLET
PRESSURE
TAP
GAS VALVE SHOWN IN OFF POSITION
FIGURE 5
White Rodgers 36G Series Gas Valve
OUTLET
P22#&E
POST
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW
GASVALVESHOWNIN OFFPOSITION
FIGURE 6
9 - Replace the unit access panel.
10 - Turn on all electrical power to the unit,
11 - Set the thermostat to desired setting.
12-If the furnace will not operate, see the section
"Turning Off Gas to the Unit" and call your service
technician or gas supplier.
B - Turning Off Gas To the Unit
1-Set the thermostat to its lowest setting.
2 - Turn off all the electrical power to the unit.
3 - Remove the heat section access panel.
4- Turn the knob on the gas valve clockwise11_' (or
move the lever) to the OFF position. Do not force.
C-Verifying the Gas Line Pressure
Check the gas line pressure while the unit is operating.
Maintain a minimum of 4.5" w.c. (1.12 kPa) and a
maximum of 10.5" w.c. (2.61 kPa). See figures 3.4, 5
and 6 for the location of the inlet pressure tap on the gas
valve.
Page 3
D - Measuring & Adjusting the Manifold Pressure
1 - Connect a manometer to outlet tap on gas valve,
2 - Start unit and allow 5 minutes for the unit to stabilize.
3 - Check the burner flame, The flame should be stable
and should not lift from the burners. The flame should
be blue and should burn continuously from all
burners.
4- After allowing the unit to stabilize for 5 minutes,
check the manifold pressure. Manifold pressure for
natural gas-fired units installed at altitudes of 7501 -
10000 ft. above sea level is 3.5" w.c. (0.87kPa). See
figures 3, 4, 5 and 6 for the location of the pressure
adjustment screws.
,IMPORTANT
NOTE -Turn off the unit and remove the manometer as
soon as you have obtained an accurate reading. Replace
the pressure tap plug.
E-Verifying the Gas Rate
The gas input must not exceed the amount shown on the
unit's rating plate. In cases where gas is not metered, the
service technician who is performing the conversion will
need to install a temporary meter to perform this
procedure. Check the input by the following method:
Contact the utility company for the heating value of the
gas. Shut offall other appliances during the input check.
Locate the meter just upstream in regulated pressure
[4.5" w.c. to 10.5"w.c. (1.12kPa to 2.61 kPa)]. To check the
Btu input rate, time the dial hand on the gas meter for at
least one revolution, using the one cubic foot dial.
To assure accurate measurements, use temperature and
pressure correction factors for the meter.
To determine the number of seconds required for the flow
of one cubic foot of gas, use the following formula:
(BTU Content)
Heating Value Of Gas X 3600
Furnace Btuh Input
Example: 1000 BTU gas
Furnace input 100,000 BTUH
Seconds for one cubic foot =
1000 X 3600 = 36 seconds
100,000
Page 4

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