12
CAST IRON STOVE AND BURNER SYSTEM
107600
For more information, visit www.desatech.com
HIGH ALTITUDE
INSTALLATION
Your FMI B-vent freestanding stove and
burner system has been AGA tested and
approved for elevations from 0-2000 feet and
CGA certified for elevations from 0-4500 feet.
When installing this stove and burner sys-
tem at an elevation above 2000 feet (in the
USA), you may need to decrease the input
rating by changing the existing burner ori-
fice to a smaller size. Reduce input 4% for
each 1000 feet above sea level. Check with
your local gas company for proper orifice
size identification and proper orifice for
your location.
When installing this stove and burner sys-
tem at an elevation above 4500 feet (in
Canada), check with local authorities.
For assistance with any high altitude installa-
tion contact DESA International’s Technical
Service Department at 1-800-DESA-LOG
(1-800-337-2564).
TROUBLESHOOTING
VENTING
PROBLEMS
Most venting problems are caused by incor-
rect vent sizing, improper installation, or
inadequate air supply. A preliminary check
for a field problem might include:
• Using a draft meter to determine if
venting system draft meets
manufacturer’s specifications
• Checking the vent sizing according to
manufacturer’s specifications, appliance
input, and venting configuration
• Examining the entire venting system for
faults such as disconnected joints for
damaged vent sections
• Making sure vent and air openings are
not obstructed
If these procedures do not reveal the source of
the problem, troubleshooting may include
attention to common venting problems.
FLUE GAS SPILLAGE
Spillage occurs when flue gases cannot exit
the vent system and back up into the dwell-
ing. A primary symptom of appliances
equipped with a Vent Safety Shutoff System
(flue spill switch) is unexplained appliance
shutoffs. Other symptoms of flue gas spillage
at the draft hood include condensation on
walls and windows and/or noticeable odors.
Spillage may also result in the release of
carbon monoxide, a colorless, odorless, highly
toxic gas. A simple spillage test can be con-
ducted if spillage is suspected. See Checking
Gas Connection, pages 14 and 15.
CAUSES OF SPILLAGE AND
CORRECTIVE ACTION
Incorrect Vent Sizing
If the vent is too small or too short, spillage
may occur. If the vent is too large, excessive
dilution air may cool flue gases and reduce
draft, causing spillage. The vent cap size
should also be checked. Check
manufacturer’s instructions, appliance in-
put rating, and appropriate sizing tables.
Venting Condition
Loose joints can affect draft and cause spill-
age. “Mashed” vent sections and damaged
vent caps can restrict flow and cause spill-
age. Examine and replace as needed.
Obstructions
Small animals or birds may get into and block
the vent or draft hood outlet. Dust, lint, and
foreign objects may obstruct air inlets. Re-
move obstructions and clean openings.
Lateral Run
Lengthy horizontal or non-vertical runs cause
resistance to flow and may reduce draft
enough to cause spillage. The pitch of lateral
runs can also be a problem; lateral runs
should be pitched 1/4" rise per foot of hori-
zontal run from the appliance to the vent.
Elbows
Too many elbows cause excessive restric-
tion of flow and may result in spillage.
Usually, two 90º turns can be tolerated in a
properly sized venting system. More than
two may cause problems and necessitate
changing the system.
VENTING
INSTALLATION
Continued
NOTICE: Consult the authority
having jurisdiction in your area
regarding listed chimney liner
venting applications.
WARNING: Operation of im-
properly installed and maintained
venting system could result in
serious injury, property damage,
or loss of life.
RELINING SYSTEMS
• Suitability and approval of relining ma-
terials should be determined.
• Condition, size, height, and termina-
tion of the chimney to be relined must
be determined.
• No substitution of components should
be made.
• Joints and connectors should be made
according to manufacturer’s instructions.
Figure 29 - Typical Straight Installation
with Listed Chimney Liner
