Lennox International Inc G50UH-36C-110, G50UH-48C-110 klMPORTANT kWARNING, VE%OO.o%OTOR

Usesheetmetalshearstoremovethecutoutfromtheside ofthecabinetUsethetwoprovidedsheetmetalscrewsto. installthecutoutonthetopcaptocovertheoriginalflue

outletopeningSeefigure15. .

TheG50UH(X)seriesunitsareclassifiedasfan-assisted CategoryI furnaceswhenverticallyventedaccordingto

thelatesteditionof NationalFuelGasCode(NFPA54/

ANSI Z223.1 ) in the USA and the current standards of CSA B149 Natural Gas and Propane Installation Codes in Can- ada. A fan-assisted Category I furnace is an appliance equipped with an integral mechanical means to either draw or force combustion products through the combustion chamber and/or heat exchanger.

NOTE - Use these instructions as a guide. They do not su- persede local codes. This furnace must be vented accord- ing to all local codes these installation instructions, and the provided venting tables in these instructions

The venting tables in this manual were extracted from the National Fuel Gas Code (NFPA 54 / ANSI Z223.1 ) and are provided as a guide for proper vent installation. Proper ap- plication, termination, construction and location of vents must conform to local codes having jurisdiction. In the ab- sence d local codes, the NFGC serves as the defining doc- ument.

Refer to the tables and the venting information contained in these instructions to properly size and install the venting system.

klMPORTANT

kWARNING

VENT CONNECTION

VENT

PIPE

FURNACE

FLUE TRANSITIOF

COLLAR

FIGURE 16

Use self-drilling sheet metal screws or a mechanical fas- tener to firmly secure the vent pipe to the round collar of the

flue transition. If self-drilling screws are used to attach the vent pipe, it is recommended that three be used. Drive one self-drilling screw through the front and one through each side of the vent pipe and collar. See figure 16.

Install the first vent connector elbow at a minimum of six inches (152 mm) from the furnace vent outlet.

Venting Using a Masonry Chimney

The following additional requirements apply when a lined masonry chimney is used to vent this furnace.

Masonry chimneys used to vent Category I central fur- naces must be either tile-lined or lined with a listed metal

lining system or dedicated gas vent. Unlined masonry chimneys are prohibited. See figures 17 and 18 for com- mon venting.

A chimney with one or more sides exposed to the outside of the structure is considered to be an exterior chimney.

An exterior masonry chimney that is not tile-lined must be lined with B1 vent or a listed insulated flexible metal vent.

An exterior tileqined chimney that is sealed and capped may be lined with a listed uninsulated flexible metal vent.

If the existing chimney will not accommodate a B1 vent or

an insulated flexible vent pipe liner, either the chimney must be rebuilt to accommodate one of these liners or an

alternate approved venting method must be found. Insulation for the flexible vent pipe must be an encapsu- lated fiberglass sleeve recommended by the flexible vent pipe manufacturer. See figure 17.

G50UH units installed in upflow applications may be vented into a tile-lined masonry chimney without using a listed metal liner, provided that the optional masonry chim- ney vent adapter kit (18M79) is used. Instructions provided with the kit must be followed exactly.

DO NOT insulate the space between the liner and the chimney wall with puffed mica or any other loose gran- ular insulating material

Common Venting Using Metal-Lined Masonry Chimney

			SEALED
			/
T	MAX. LENGTH
	-- SEE NOTE 1
	BELOW.	II
		II	CHIMNEYEXTERIORWITH
		II	METAL
VE%OO.o%OTOR "		II	LINER
		'1

__ .,J

PERMANENTLY

SEALED FIREPLACE

OPENING

NOTE 1 - Refer to the provided venting tables for installations in the USA and the venting tables in CSA B149 for installations Canada.

NOTE 2 - Either single-walledor double-walled vent connector may be used. Refer to the capacity requirements shown in the provided venting tables for installations in USA and the venting tames in current CSA B149 for installations in Canada.

FIGURE 17

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