Weil-McLain Ultra Manual page 39

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gas fired water boiler
Sidewall vent/air termination:
Allowable vent/air pipe materials
1. Use only the materials listed in
2. Purchase termination plates and bird screens separately. See the
parts list at the end of this manual.
Maximum piping length
1. Locate the terminations such that the total air piping and vent pip-
ing from the boiler to the termination will not exceed the maximum
length given in Figure 48.
2. Maximum lengths listed in
elbows required a reduction in maximum length as explained in
the table notes.
Connecting from termination to boiler
1. Install the terminations as instructed in the following. Then pro-
ceed to page 48 to complete the air and vent piping between the
termination and the boiler.
Determine location — separate elbows
A gas vent extending through an exterior wall shall not
terminate adjacent to the wall or below building exten-
sions such as eaves, parapets, balconies or decks. Failure
to comply could result in severe personal injury, death
or substantial property damage.
1. Locate the vent/air terminations using the following guidelines.
2. The air piping must terminate in a down-turned elbow as shown in
Figure 49. This arrangement avoids recirculation of flue products
into the combustion air stream.
a. Apply the configuration on the left side of
the terminations would fail to meet minimum clearance to
grade or snow line.
b. Apply the configuration on the right side of
the terminations need to be raised higher to meet clearance to
grade or snow line.
c. The vent and air pipes may run up as high as 4 feet, as shown in
Figure 49 right side with no enclosure. The vent and air pipes
must be secured with braces, and all clearances and lengths
must be maintained. Space braces no further than 24 inches
apart. (See WARNING below for extremely cold climates.)
d. External venting greater than 4 feet requires an enclosure
around the vent and air pipes. The vent and air terminations
must exit through the enclosure as shown in Figure 49, main-
taining all required clearances.
3. The vent piping must terminate in an elbow pointed outward or
away from the air inlet, as shown in Figure 49.
Do not exceed the maximum lengths of the outside vent
piping shown in Figure 49. Excessive length exposed to
the outside could cause freezing of condensate in the vent
pipe, resulting in potential boiler shutdown. In extremely
cold climates, install an insulated chase around the vent
piping, particularly when using longer lengths. The chase
must allow for inspection of the vent pipe, and insulation
must be protected from water.
Part number 550-100-066/0608
— Boiler Manual
Figure 32, page 31.
Figure 48 allow for 2 elbows. Additional
Figure 49 unless
Figure 49 when
Separate pipes
Figure 48
Maximum piping lengths for separate vent
and air pipe sidewall termination
Boiler Maximum
Ultra– Piping, 2" * Piping, 3" *
Feet Elbows Feet
80 30 2 100
105 30 2 100
155 Not allowed 100
230 Not allowed
310 Not allowed Not allowed
* Install pipe reducers to adapt from pipe size used to the
3.5-inch outside diameter required at the termination. You do
not have to reduce allowable pipe length for the reducers. Also
install reducers as necessary where connecting to the boiler
vent and air connections.
For piping using more than 2 elbows, reduce maximum allow-
able length:
• 7 feet for each additional 4-inch elbow (90° or 45°)
• 7 feet for each additional 3-inch long radius elbow
• 16 feet for each 3-inch short radius elbow
• 7 feet for each 3-inch 45-degree elbow.
Figure 49
Sidewall termination — separate pipes
— configuration options and minimum
clearances from vent to air terminations
Maximum Maximum
Piping, 4" *
Elbows Feet Elbows
2
Not
2
allowed
2
30 2 100 2
100 2
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