Lennox Hearth ELITE VISN-25/35 - Manuel (Page 15)

15
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE. NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Storm Collar
Vertical Termination
Cap
Ceiling Firestop
Framing 10”x 10”
Roof - Maintain 1”
Clearance to
Combustibles
Pipe
Length
Flashing
Hand break to remove
unwanted restrictor
Light Obstructor
(only used for Vision25 w/short
horizontal run & no flue restrictor)
Position 1 Flue Restrictor Position 3 Position 2
A
Vertical Vent Installation
Important Notes
1. All vertically terminated vent installations use 6­5/8” x 4”
Security™ Secure Vent™ pipe*.
2. If the vent passes through a ceiling or floor, a firestop ­ Simpson
#963 or Security #SV4BF ­ is required.
3. If the vent passes through the roof, a roof flashing ­ Simpson
#943 or 943S or Security #SV4FA or SV4FB ­ and storm collar
­ Simpson #953 or Security #SV4FC ­ are required.
4. A 1­inch clearance from the vent pipe to combustible materials
must be maintained.
5. A maximum of either two 45º elbows or two 90º elbows may
be used. See Page 16 for allowable offsets.
6. The maximum system height is 30 feet (9.1M) and the minimum
is 10 feet (3M).
14” Snorkel
min 12”
Figure 17
Figure 16
Figure 18
Flue Restrictors
The flue restrictor settings shown in Figures 19 and 20 are for typical
installations and may need to be adjusted from standard to take into
account other variables in the installation to achieve proper combus-
tion. See Flue Restrictor Guidelines on this page to assist you in
making a proper flue restrictor adjustment.
This stove requires a balanced flue to ensure proper combustion. As
such, flue restrictors may need to be installed depending on the vent
configuration of your stove. The drawings on the following page show
all the allowable pipe configurations for this appliance. To properly in­
stall the flue restrictor, find your pipe configuration in the drawings on
the following page and note which restrictor setting is recommended.
The flue restrictor is shipped in the firebox of your stove. To install the
restrictor, see Figure 18. Remove the two 5/32” allen head screws (A
below). Using pliers, repeatedly bend the unwanted portion of the flue
restrictor and discard. Install the flue restrictor using the two 5/32” allen
head screws according to the diagram below. Install the flue restrictor
screws in their original holes in the top of the firebox. Restrictor posi­
tions are based on tests run in a laboratory.
Flue Restrictor Adjustment Guidelines
After the flue restrictors have been changed to the standard flue restrictor
settings as shown in Figures 19 and 20, the burner flame appearance
should be evaluated to determine if the 1, 2 or 3 flue restrictor standard
settings were the correct adjustment for variables in your installation.
Light the appliance and allow it to burn for 20 minutes on the high setting.
See Flame Color and Behavior on Pages 21 and 22 to determine if you
have a proper burner flame appearance. If the proper flame appearance
cannot be achieved, the flue restrictor may need to be changed to a dif­
ferent position (1, 2 or 3). See the following guidelines to determine if
you need to readjust the flue restrictors.
Before proceeding, confirm the manifold and inlet gas pressure is correct,
primary air shutter is properly adjusted, venting system connections are
secure and not blocked and if you are at a high elevation, ensure unit
has been properly derated:
Symptoms - Lack of Combustion Air
If the symptoms listed below are present, you may need to adjust the
flue restrictor to a more open position.
• Flame appears yellow
• Floating Flames (lazy, ill defined, quiet, may roll)
• Sooting
• Pilot becomes yellow and appliance shuts down
Symptoms - Excessive Combustion Air
If the symptoms listed
below are present, you
may need to adjust the
flue restrictor to a more
closed position.
• Low Flame
• Pilot pulls and appliance
shuts down
• Pilot flame ghosts