General Lennox Merit Series ™ E Or Ec Series; Gas Piping - Lennox Merit Series Installation Instructions Manual

GENERAL E OR EC SERIES
THERMOSTAT INSTALLATION
Install a room thermostat according to the instructions
furnished with it. Select a location on an inside wall and not
subject to drafts, direct sunshine or other heat sources. The
initial heat anticipator setting should be equal to the total
current draw of the control circuit.
FURNACE CHECk-OUT
Before leaving, the installer should make the following
checks to ensure that the controls are functioning properly.
CHECkING AND ADJUSTING GAS INPUT
The minimum permissible gas supply pressure for the purpose
of input adjustment is listed on table 4 of this manual.
GAS PRESSURE REGULATOR
Gas input must never exceed the value shown on the
furnace rating plate.
The manifold pressure can be measured by connecting
a water manometer or gauge to the pressure tap in the
downstream side of the gas valve.
Only small variations in gas input may be made by adjusting
the regulator. In no case should the final manifold pressure
vary more than 0.3 in. W.C. (0.07kPa) from the above
specified pressures.
TEMPERATURE RISE
Check the temperature rise and, if necessary, adjust blower
speed to maintain temperature rise within the range shown
on the unit rating plate.

GAS PIPING

GAS SUPPLY
This unit is to be installed by a licensed gas
plumber fully in accordance with AG601 installation
regulations.
1. This unit is shipped standard for centre installation of gas
piping. Piping can be converted for right-side connection.
Simply connect gas supply to piping assembly.
2. When connecting gas supply, factors such as length
of run, number of fittings and furnace rating must
be considered to avoid excessive pressure drop. Unit
connection at gas manifold is 1/2 in. (12mm). Size piping
according to gas regulations.
3. Gas piping must not run in or through air ducts, clothes
chutes, chimneys or gas vents, dumb waiters or elevator
shafts.
4. Piping should be sloped 6mm per 380mm upward toward
the meter from the furnace. The piping must be supported
at proper intervals (2m) using suitable hangers or straps.
5. In some localities, codes may require installation of a
manual main shut-off valve and union (furnished by
installer) external to the unit. Union must be of the ground
joint type.
IMPORTANT
!
Compounds used on threaded joints of gas
piping must be resistant to the actions of
liquified petroleum gases.
NOTE: Installer must provide a 3mm N.P.T. plugged tap in
the field piping upstream of the gas supply connection to the
unit. Tap must be accessible for test gauge connection. This
requirement is negated if the gas valve in the unit is fitted
with an integral pressure tapping point.
NOTE: If emergency shut-off is required, shut off main
manual gas valve and disconnect main power to unit. These
devices should be properly labelled by the installer.
LEAk CHECk
After gas piping has been completed, carefully check all
piping connections (factory and field) for gas leaks. Use a
leak detecting solution or other preferred means.
CAUTION
!
Some soaps used for leak detection are
corrosive to certain metals. Carefully rinse piping
thoroughly after leak test has been completed.
Do not use matches, candles, flame or other
sources of ignition to check for gas leaks.
The furnace must be isolated from the gas supply system
by closing its individual manual shut-off valve during any
pressure testing of the gas supply system at pressures equal
to or less than 1/2 psig (3.48 kPa).
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