10
3-90-233R24_11/13
The minimum vent configuration is a 90° or Tee on a starter
collar and a 24” length horizontal through an exterior wall. A
cap on the end should direct the flue gases down and away
from the structure. See Fig. 5.
The maximum horizontal length is 8 feet. The minimum
termination height above the exterior grade is 18”. The
maximum total length of any configuration is 18 feet*.
* (see venting graph on page 10 for exceptions)
NOTE: Cleanout Tee’s should always be used on the
transitions to horizontal pipe to allow easy access for
cleaning.
The venting graph allows for one(1) 90 deg. or Tee fitting in
any configuration.
If more 90’s, T’s, or 45’s are needed the total length must be
adjusted to allow for the added restriction.
Up to four (4) additional 90’s, Tee’s, or equivalent 45’s can be
added as long as the overall length is adjusted in accordance
with the values listed below.
(See the venting graph on page 10.)
Each Vertical------ 90° or T subtract 2.5 feet
Each Vertical------ 45° subtract 1.5 feet
Each Horizontal-- 90° or T subtract 5.0 feet
Each Horizontal-- 45° subtract 2.5 feet
venting
3” Type “L” or
“PL” Vent pipe
This is the minimum venting configuration. NOTE: A starting collar
is needed in order to remove the units’ cleanout cover.
Fig. 5
Any exterior venting (vent pipe exposed to outside
ambient temperatures) should be kept to a minimum,
due to potential condensation problems.
This is
especially important in high humidity-cold weather
climates, such as maritime areas, lake shores, and low
river valleys.
venting Into An Existing Chimney
The boiler may be vented into an existing masonry or Class
A metal chimney, providing that the chimney is less than 20
feet above the connector. A flue liner, no more than 4-inch
diameter, must be installed, along with a termination cap and
the proper flashing to seal the existing flue.
The venting Can Not
be installed in a chimney serving
another appliance.
The chimney should be cleaned and/or inspected before
installation of the vent liner.
Due to low exhaust temperatures, and the increased
possibility of condensation and creosote formation, additional
measures may need taken to increase the flue temperature.
One such measure would be to remove the two rear-most
spiral baffles, above the burn pot, from their heat exchange
tubes. Although some efficiency will be lost, an increased
flue temperature will result.
The flue liner should be inspected frequently, during
operation, to monitor its performance and cleanliness.
Other examples of possible installations of the venting.
12”
36”
12”
36”
NOTE: Use only 3” diameter type “L” or “PL” venting
system. Be sure to inspect and clean exhaust venting
system frequently.
