Lennox International Inc. TUA125S Benutzerhandbuch

Page 4 

 

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45, 60, and 75 size units may be installed in the normal 
position or inverted 180° as shown in figure 1 depending 
on desired location as governed by clearances, vent 
connection, air direction, gas supply, electrical supply 
and service accessibility. 

1-  Rotate louvers directing airflow as desired. 
2-  Choose location for mounting brackets. 
3-  Remove the mounting brackets from their shipping 

location (attached to the top of the unit) and replace 
the screws that held the brackets in their shipping 
location. 

4-  Remove and retain screws along top edge (bottom 

edge when inverted) of front of unit. 

5-  Align screw holes on mounting bracket with holes 

along top edge (either upright or inverted) of unit. 

Secure mounting brackets to unit with retained 
screws.  

6-  To support unit, secure mounting bracket to ceiling 

joist or truss. Unit may also hang on rods as shown 
in figure 1. 

100 and 125 size units may not be inverted, 3/8” X 16 
threaded inserts are provided in the top the cabinet.  
Two threaded inserts are along one edge of the cabinet, 
two inserts are in the panel that divides the heat 
exchanger section from the control compartment. 

1-  Cut threaded rods to desired length and thread a 

3/8” nut onto the rod. 

2-  Slide a flat washer onto the threaded rod AFTER 

the nut (7/16” I.D. X 1” O.D. X 1/16” THK washer). 

3-  Screw the rods (four) into the threaded inserts on 

the unit. 

4-  Tighten nuts to secure unit to rods. 

 

 

Adequate facilities for supplying air for combustion and 
ventilation must be provided. All gas fired appliances 
require air to be used for the combustion process. If 
sufficient quantities of combustion air are not available, 
the heater or another appliance will operate in an 
inefficient manner, resulting in incomplete combustion 
which can result in the production of excessive carbon 
monoxide. 

This unit must be provided with a combustion air pipe 
that is connected to the outside atmosphere. Outdoor 
air used for combustion must be free of the following 
substances or the life of the heat exchanger will be 
adversely affected: chlorine, carbon tetrachloride, 
cleaning solvent, halogen refrigerants, acids, cements 
and glues, printing inks, fluorides, paint removers, 
varnishes, or any other corrosives. 

TABLE 2 

MAXIMUM  HORIZONTAL VENT LENGTHS 

Model 

45, 60, 75 

100, 125 

No. of Elbows 

Ft (M) 

Ft (M) 

1 

25 (7.6) 

25 (7.6) 

2 

20 (6.1) 

20 (6.1) 

3 

15 (4.6) 

15 (4.6) 

4 

10 (3.0) 

10 (3.0) 

5 

5 (1.5) 

5 (1.5) 

   

FIGURE 1 

INSTALL UNIT HEATER