pellet stove installation
Installing a freestanding pellet stove
is much like installing a conventional wood burning stove. By contrast,
a pellet stove insert is
designed to fit into an existing fireplaces. Whether you intend to do the
installation yourself or have a dealer do it, it's vital for both the safety
and efficiency of operation that the manufacturer's guidelines be followed.
Placement of a pellet stove
To get the most pleasure and effective heating from your stove, it's usually
a good idea to install it in a central living area. It then makes an attractive
focal point for the family and the heat it gives out can flow out from this
room to other areas of the house. A number of key factors have be considered
before installation can get underway.
Unless you already have a suitable hearth in place on which to put your
stove, you'll need to have floor protection laid down that meets the manufacturer's
specs, including minimum size and type of material. If in doubt get professional
advice. Built-in appliances may need extra protection such as an air space
between the appliance and the floor protector.
Find out if this likely to be limited by factors such as obstructions
above vertical venting through the ceiling and roof or by the distance
to an outside wall for horizontal venting.
Outside air for combustion (if needed)
This has to be drawn from an approved location.
There are minimum specified clearances between the stove and combustibles.
But allow more space than the minimum to give enough room to operate and
service the stove easily.
Because a pellet stove needs electrical power, it has to be located near
a properly wired outlet of the correct voltage, ground, and polarity.
It's also essential that the circuit to be used has a properly rated circuit
Proper venting is vital to for the performance of your stove, safety, keeping
maintenance to a minimum, and the quality of the indoor environment. Pellet
stoves produce hardly any visible smoke after startup, but exhaust gases,
fine ash, and water vapor have to be removed safely from the appliance to
the outdoors without leaking into the house. The purpose of all vents is
removing combustion byproducts during normal operation. For most designs,
the exhaust is mechanical: a fan blows the combustion byproducts out and
draws air needed for combustion into the fire. A few stoves operate without
a combustion air fan and use natural draft both for exhaust and combustion
air intake. Some heat also moves through the vent. Protection of nearby
combustibles is essential. The minimum clearance between the vent and combustibles,
as specified in the vent installation instructions, must be met or exceeded
to assure safety.
The product specifically tested and listed for use with pellet stoves is
PL vent pipe, labeled 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 requiring PL vent must use
no substitute venting materials.
Venting materials and products that MUST NOT BE USED TO VENT PELLET APPLIANCES
- 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 wood stove chimneys (Fig. 1). 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.
| Fig. 1
| Fig. 2
| Fig. 3
| Fig. 4
| Fig. 5
| Fig. 6
The options for venting layout fall into the following categories:
Besides appliance requirements, several other factors may be considered
in specifying pellet venting systems. The following factors may play a role
in the designation of the venting system:
Sidewall horizontal venting(Fig. 2)
Invariably the least expensive venting system. Disadvantage of potential
smoke spilling into the house in the event of a power outage or component
failure, or house depressurization.
Horizontal vent with backup vertical venting (see Fig. 3)
Preferred horizontal method that avoids venting problems associated
with unexpected appliance shutdown.
Vertical venting through the ceiling and roof (Fig. 4 and 5)
Has the advantages of keeping vent gases warm and of providing natural
draft to prevent problems in an unexpected shutdown.
Venting into existing chimney (see Fig. 1)
Stove manufacturers provide recommendations for venting into masonry
and factory-built chimneys, which may include partial or full chimney
All vents for appliances designed without mechanical exhaust fans must
meet stove manufacturer's requirements for minimum draft and must terminate
above the roof.
Horizontal and vertical (Fig. 6)
Extends from the top or back of the appliance, penetrates the wall,
turns up to penetrate the eave and roof.
When assembling and joining together pellet venting components, 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.
High altitude installations, generally higher than 2500 feet above sea
level, may require special venting options to provide adequate combustion
air and/or draft.
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.
Unpredictable effects of high winds or prevailing wind conditions may
necessitate the addition of vertical venting extending above the roof
and/or special termination caps.
Cleanout and Maintenance
The venting system must be designed with normal maintenance in mind.