Lennox International Inc. GWB9-075IH-2 Manuel D’Utilisation

Check to be sure you have selected boiler with proper 

capacity before starting installation. AHRI Rating of boiler 

selected should be greater than or equal to calculated 

peak heating load (heat loss) for building or area(s) served 

by boiler and associated hot water heating systems. See 

 Table 1, Page 5 . 
Heat loss calculations should be based on approved 

industry methods.

Before selecting boiler location consider following. 

• Supplied with correct type of gas (natural gas or 

propane).

• Connected to suitable combustion air intake piping 

system to supply correct amounts of  fresh (outdoor) 

air for combustion, refer to  “Combustion Air and Vent 

Pipe” on page 22  for details.

• Connected to a suitable venting system to remove 

the hazardous products of gas combustion, refer to 

 “Combustion Air and Vent Pipe” on page 22  for details.

• Connected to a suitable hot water heating system.
• Supplied with a suitable electrical supply for all boiler 

motors and controls.

• Connected to a properly located thermostat or 

operating control. Not included with boiler.

• Placed on level surface. DO NOT install on carpeting.
• Condensate drain line must be pitched down to fl oor 

drain or external condensate pump with reservoir at ¼” 

per foot (wood frame or blocks may be used to raise 

boiler).

Boiler is equipped for residential installations. If used 

for commercial applications, any additional code 

requirements must be adhered to for installation. This 

may require additional controls including but not limited 

to a low water cut off, a manual reset high temperature 

limit, and wiring and/or piping modifi cations. 

Before servicing boiler - allow boiler to cool. Shut off 

electricity and gas supply connected to boiler prior to 

servicing.

Inspect gas line for leaks.

Verify gas input rate is correct. Over fi ring may result 

in early failure of boiler sections. This may cause 

dangerous operation. Under fi ring may result in too 

much air for pre-mix burner causing poor or loss of 

combustion.

Never vent products of combustion from this boiler to 

enclosed space. Always vent to outdoors. Never vent to 

another room or to inside building.

Be sure there is adequate outdoor air supply to boiler 

for complete combustion.

Follow regular service and maintenance schedule for 

effi cient and safe operation. 

Keep boiler area clean of debris and free of combustible 

and fl ammable materials.

Proper through wall or through roof combustion venting 

shall be in accordance with materials and methods 

described in this manual. Installation must comply with 

local codes.

Boiler and related hot water heating systems are not do 

it yourself items they must be installed and serviced by 

qualifi ed professionals.