PLACEMENT AND USE OF WOOD PELLET
STOVES
What factors determine appliance location?
For maximum enjoyment and heating effectiveness, a major
living area where the family spends leisure hours and which provides
heat flow to other areas is usually a strongly preferred location for
the stove. The pellet heating professional considers the following
factors when determining whether installation requirements can be met in
the homeowner's preferred location:
Venting may be limited by factors like obstructions above for vertical
venting through the ceiling and roof, or by the distance to an outside
wall for horizontal venting.
Outside air for combustion, if needed, must be drawn from an approved
location.
Space requirements must meet minimum clearances between the stove and
combustibles. More space than the minimum required may be desirable to
provide room for convenient operation and service.
Electrical requirements - Proximity to a properly wired outlet.
What are my choices for floor protection?
The floor must be protected according to the pellet stove manufacturer's
instructions. The minimum size of the non combustible floor protector is
clearly specified in installation instructions. The choice of suitable
material usually requires professional assistance, unless a suitable
hearth is not already available in the home. Built-in appliances may
require additional layer of protection, such as an air space between the
appliance and the floor protector.
What electrical requirements should be checked?
The dealer or installer should check the intended appliance
outlet for proper voltage, ground, and polarity. The electrical circuit
to be used should have a properly rated circuit breaker.
•Are there special requirements for mobile home installations? The model
you choose must be approved for use in a mobile home.
VENTING
What are the purposes of venting systems?
Proper venting is essential for proper appliance performance, dwelling
safety, maintenance frequency and indoor environment. Pellet stoves
produce little or no visible smoke after startup, but exhaust gases,
fine ash and water vapour must be moved safely from the appliance to the
outdoors without leaking into the house. The purpose of all vents is to
remove combustion by-products produced during normal operation. For most
designs, the exhaust is mechanical: a fan blows the combustion
by-products out and pulls air needed for combustion into the fire. A few
stoves operate without a combustion air fan and instead use natural
draft both for exhaust and combustion air intake. Some heat also moves
through the vent, making protection of nearby combustibles essential.
The minimum clearance between the vent and combustibles, as specified in
the vent installation instructions, must be met or exceeded to assure
safety.
What materials and products can be used to vent pellet stoves?
The product specifically tested and listed for use with pellet stoves is
PL vent pipe, labelled as tested to UL 641. PL vent pipe is double wall
pipe; the stainless steel inner pipe that carries the exhaust products
is separated from the outer wall by an air space. Pipe joints must be
sealed gas tight to prevent exhaust products moving through the vent
under pressure from leaking into the home. Stoves tested and listed with
PL vent requirements cannot safely be vented with substitute materials.
Venting materials and products that MUST NOT BE USED TO VENT
PELLET APPLIANCES include:
Dryer vent
Gas appliance (Type B) vent
PVC (plastic) pipe
Single wall stove pipe (unless clearly approved by the installation
manual and local codes)
Pellet fireplace inserts and freestanding stoves are often vented into
existing masonry and factory-built fireplace and woodstove chimneys. The
chimney should be inspected before installation to ensure that it is
clean, mechanically sound and meets local safety code requirements. The
appliance manufacturer's installation instructions may require relining
the chimney with an approved metal liner, pipe or PL vent. Vents or
grilles on the face of factory-built fireplaces which provide cooling
air to the outside jacket of the fireplace must not be blocked. Cleanout
access for future maintenance should be considered.
What are my options for venting layout?
Mechanical Exhaust:
Sidewall horizontal venting: Invariably the least expensive venting
system. The disadvantage of potential smoke spilling into the house in
the event of a power outage or component failure, or house
depressurisation (see discussion of next question).
Horizontal vent with backup vertical venting: Preferred horizontal
method that avoids venting problems associated with unexpected appliance
shutdown.
Vertical venting through the ceiling and roof: This has the advantages
of keeping vent gases warm and of providing natural draft to prevent
problems in an unexpected shutdown.
Venting into an existing chimney: The Stove manufacturer shoud provide
recommendations for venting into masonry and factory-built chimneys,
which may include partial or full chimney relining.
Natural Draft: All vents for appliances designed without mechanical
exhaust fans must meet stove manufacturer's requirements for minimum
draft and must terminate above the roof.
Besides appliance requirements, what other factors may be considered in
specifying pellet venting systems?
The following factors may play a role in the designation of the venting
system:
Altitude: High altitude installations, generally higher than 2500 feet
above sea level, may require special venting options to provide adequate
combustion air and/or draft.
House Pressure: Extremely tight house construction or strong kitchen,
bath or other exhaust fans may create a negative pressure within the
home that decreases venting effectiveness. May necessitate an approved
outside air source.
Windy Conditions: Unpredictable effects of high winds or prevailing wind
conditions may necessitate the addition of vertical venting that extends
above the roof and/or special termination caps.
Cleanout and Maintenance: The venting system must be designed with
normal maintenance in mind.
How should pellet venting components be assembled and
joined together?
Appliance manufacturer's instructions should be followed
closely regarding sealing joints and seams, particularly of pressurized
mechanical exhaust vents. It is imperative that they be gas tight so
that they cannot leak. Proper application of an approved sealant or
sealing band is typically required. Appliance manufacturer's
instructions for pipe sealing which exceed vent manufacturer's
instructions must take precedence. You can get a sense of what heating
with pellets involves through an introduction to the principles of
operation and the reasons for maintenance that you will come to
understand as an experienced operator.
OPERATION
What's a good starting point for learning to operate a pellet
stove?
The rule here is "Before all else fails, read the instructions."
Operating a pellet stove is not difficult, but it is a new technology
that calls for basic knowledge. Training videos accompany some stoves,
and hands-on demonstrations are offered by many dealers and installers.
How do I start a fire?
Small dry fuel (pellets) and combustion air (provided by a
fan on most designs) make startup easy. Operating instructions
accompanying the stove give the specific steps to follow. Manual
ignition stoves call for the owner to apply an approved gel or solid
starter material (no liquids), light the pellets, and monitor the fire
to see that the fire catches and the flame gradually grows. On automatic
ignition stoves, pressing the start button feeds pellets to the burn pot
and heats the self-igniter device.
What if the stove doesn't start properly?
A safety device monitors startup and stops fuel feed if operating
temperatures are not reached within a specified time period. If startup
fails, the operator should first make sure that the hopper has fuel and
that fuel is feeding into the burn pot, and then attempt to restart the
stove. Repeated failed lighting cycles indicate the need for maintenance
or professional service.
What do I do after the stove starts?
After control panel or air inlet adjustments and a quick
performance check, the stove is set to provide hours of even,
comfortable heat. Stoves equipped with a remote wall thermostat respond
to a set room air temperature by cycling on and off or by cycling from a
low to high burn, depending on stove startup design.
What are signs of performance problems?
Properly operated and maintained pellet stoves experience
few, if any, problems. Most of pellet stove operation is automatic, but
sometimes combustion air adjustment is needed. A lazy, orange, sooty
flame or dark smoke coming out of the vent (after startup and before
shutdown) may indicate the need for more air. An overactive, "blow
torch" flame calls for less air. Performance problems are more likely to
be caused by neglected maintenance than by regular operation. Lazy
flame, dark smoke, unusual sooting of glass, unexplained smoke spillage
and reduced heat output all point to the need for maintenance of
appliance components and/or the venting system, or for remedies for
house depressurization. Problems related to mechanical failure usually
results in safety switches shutting the appliance down. Appliance
shutdowns may, however, indicate nothing more than owner forgetfulness
(empty hopper) or hurry (improper startup), or intermittent power
failure. Unexplained, repeated appliance shutdowns call for professional
advice and service.
How do I shut the stove down?
Shutting the stove down is typically a matter of simply
setting the control to the “Off” position according to operating
instructions. The fuel feed stops delivering fuel right away, and after
the stove cools sufficiently, all motors and blowers cease operation.
The stove should NOT be shut down by unplugging the power cable.
What happens in an unexpected shutdown such as a power
outage or component failure?
Although fuel feed stops in a power outage, the pellets in
the burn pot may continue to burn or smoulder. The duration of this
condition can vary with appliance design from a few minutes to an hour
or more. The resulting smoke and hot gases rise, seeking the path of
least resistance. If the exhaust vent does not have vertical sections to
provide natural draft, smoke may spill into the home.
MAINTENANCE
What are the routine things that I do to keep my stove
working right?
Routine maintenance tasks are essential to peak stove performance:
Burn pot:
Checked daily and cleaned periodically to keep air inlets
open. Frequency of cleaning depends on fuel type, grade, and content.
Ash drawer:
Emptying recommended before starting new fires and
occasionally during stove operation. Frequency depends on fuel and stove
design. Typically once or twice a week, but monthly in some new designs.
Heat exchanger:
On some stoves, its simply a matter of moving a rod that
scrapes the tubes inside the stove. Some types may require professional
service.
Ash traps:
Chambers located behind the fire chamber which prevent excess
fly ash in the exhaust from exiting the stove. Easily accessed for ash
removal by owners in some designs; on others, professional service is
required.
Glass:
Clean with glass cleaner, when the glass is completely cool,
on stoves with effective air wash systems, these may require more
vigorous methods than on others. Should the alignment be this way (over
to the right)
Hopper:
Checked for accumulated sawdust materials (fines). Fuel in
the hopper and auger tube should be emptied occasionally to prevent
auger blockage by fines.
What are some of the more advanced maintenance tasks?
Cleaning the venting system is usually performed by
professionals but can be tackled by the handy stove owner with thorough
knowledge and the right equipment. Motors and fans need occasional
cleaning and may require lubrication. The wrong lubricant or wrong
amount of lubricant can damage components. Some components which call
for removal for service require the replacement of a gasket.
Additionally, gaskets for the fire chamber door, ash pan door and hopper
lid (on some designs) may need occasional replacement to assure a tight
seal.
What professional maintenance and repair services will
I need?
Most pellet stove owners depend on professional service for cleaning and
preventive maintenance on at least an annual basis. The dealer should
offer a service plan offering reduced costs and convenient scheduling.
Cleaning and maintenance services usually performed include:
Emptying ash traps and cleaning exhaust passages behind the fire
chamber.
Cleaning and lubricating fans and motors.
Cleaning the hopper and fuel feed system.
Cleaning the heat exchanger system.
Cleaning exhaust pipes and resealing the venting system if needed.
Verifying and adjusting the stove settings with proper gauges and
meters.
Mechanical and electric components may eventually wear out and need
repair or replacement.
Many manufacturers now offer low-cost, high-value extended warranties on
electrical components. You can also benefit from professional advice
that helps you improve stove performance and convenience with operating
tips or fuel information.
How do I select a service technician?
Finding competent in-home service should really be part of
the buying decision, since service is needed at least on an annual
basis. A reputable stove shop or service technicians should offer a
service plan that specifies a service schedule, what is covered, travel
costs and other details. One way to assess service record is to ask for
references. Another is to look for technicians who have taken the
national exam to become certified by the SEI.
Experienced pellet burners reap rewards for shopping and planning
carefully and learning to operate and maintain their pellet heating
system. They understand that pellet stoves contribute dramatic
improvement in convenience to the long tradition of the hearth. The fuel
itself is easily and cleanly stored and handled in bags. A single
loading of a pellet stove can provide long hours of warmth. Pellet
stoves also provide a special comfort associated with wood burning. The
combination of fans delivering warm air currents and the direct comfort
of radiant heat provides special satisfaction on a cold winter day. The
heat provided is even and constant, due to the automatically regulated
fuel feed responding to owner settings. Pellet stoves also offer strong
environmental benefits; pellets not only reduce dependence on finite
supplies of fossils fuels like oil and gas, but they also put to good
use materials that would otherwise unnecessarily and expensively add to
our waste disposal problems. In addition, pellet stoves burn very
cleanly and offer the lowest emissions of unwanted pollutants of all
solid fuel burning appliances. Burning biomass pellets offers convenient
heat delivered with environmental concern.
For further information and advice, talk to the company with the WOW
factor.