Takagi T-KJr2U-IN Installation Manual And Owner's Manual page 14

This is a Category III appliance and must be vented accordingly. The vent system must be sealed air tight.
All seams and joints without gaskets must be sealed with high heat resistant silicone sealant or UL listed
aluminum adhesive tape having a minimum temperature rating of 350 °F (177 °C). For best results, a vent
system should be as short and straight as possible.
• This water heater is a Category III appliance and must be vented accordingly with any 4 in. (102
mm) vent approved for use with Category III or Special BH type gas vent.
• Follow the vent pipe manufacturer's instructions when installing the vent pipe.
• Do not common vent this appliance with any other vented appliance (Do not terminate vent
into a chimney. If the vent must go through the chimney, the vent must run all the way through
the chimney with Category III approved or Special BH vent pipe).
• When the horizontal vent run exceeds 5 ft. (1.5 m), support the vent run at 3 ft. (0.9 m) intervals
with overhead hangers.
• The maximum length of exhaust vent piping must not exceed 50 ft. (15.2 m) (deducting 5 ft.
(1.5m) for each elbow used in the venting system). Do not use more than 5 elbows.
Diameter
4 in. (102 mm)
*For each elbow added, deduct 1.5m (5 ft.) from max. vent length.
No. of Elbows
0
1
2
5
Excludes elbow termination, rain caps, or the 4 in. (102 mm) PVC Concentric Termination
-DIPswitch settings for Direct Vent models-
Set DIPswitches shown in the table below depending on the vent length.
110U Direct vent (T-KJr2U-IN)
310 Direct vent (T-K4U-IN)
ON 1 2 3 4 5 6 7 8 9 10
OFF
No. 6 : ON
No. 7 : OFF
ON 1 2 3 4 5 6 7 8 9 10
OFF
No. 6 : ON
No. 7 : ON
-Vent length and No. of Elbow-
Max. No. of Elbow Max. Vertical and Horizontal (Total) Vent Length
5
Max. Vertical or Horizontal Vent Length
510U Direct vent (T-D2U-IN)
(Upper bank of DIPswitches)
ON 1 2 3 4 5 6 7 8
OFF
ON 1 2 3 4 5 6 7 8
OFF
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Page
Installation Manual
50 ft. (15.2 m )
50 ft. (15.2 m)
45 ft. (13.7 m)
40 ft. (12.2 m)
25 ft. (7.6 m)
Vent length
0 to 30 ft
No. 3 : ON
No. 4 : OFF
31 to 50 ft
No. 3 : ON
No. 4 : ON
Installation