Installation guide

Single Wall Venting (Room Air Dependent)
73
General Installation Information (continued)
Additional requirements for stainless steel vent pipe material (continued)
Table 48. Coaxial increaser
(min. stainless steel pipe diameter is 3” / 76mm)
The coaxial increaser is required for the following boiler models.
Supplier
Boiler Model Ø inches
mm
Qty.
Viessmann H WB1B 10-29, 10-35
WB2B 8.5-19/26/35
2to 3
60 to 80
1
Coaxial increaser D for
WB1B 10-26, 10-35 and WB2B 9-19, 9-26, 9-35
Legend
Optional opening for combustion
air intake
B Air intake cover
C Boiler a daptor
D Coaxial increaser, 60/100, 80/125
(2” to 3”)
E 3” diameter stainless steel starter
adapter (max. insertion 2½” / 64mm)
5368 815 v2.0 b
b
a
Flue
Combustion
air
Remove and discard
air intake cover.
C
D
E
a 6.25” / 159 mm
b 10.34” / 263 mm
Fig. 58
A
Remove and
discard air inlet
cover when
installing coaxial
vent pipe system.
B
B
Remove and discard cover B if
used in addition to annular air gap
Fig. 59