17
WinterWarm Fireplace Insert or System
2000941
Section III: Preparing a Masonry Chimney
Installing the WinterWarm into a masonry fireplace is an
effective way to add an efficient heater to your home.
Requirements for the
Existing Masonry Fireplace
The WinterWarm Fireplace Insert is listed only for
installation within a properly built masonry or heat
circulating, masonry-type fireplace that is constructed in
accordance with the requirements of recognized
building codes. A heat-circulating masonry-type fire-
place must conform to building code standards for
masonry fireplaces, and must consist of a factory-built
metal firebox with air circulation pathways that are
surrounded by masonry materials.
NOTE: The WinterWarm is not listed for use in
“zero-clearance” prefabricated fireplaces, except
when used as part of the Vermont Castings’
WinterWarm Fireplace system, including the
WinterWarm Fireplace Energy Cabinet, item #2110
(referred to on the WinterWarm safety label as
Fireplace Cabinet Model 1283).
The fireplace and chimney must be clean and structur-
ally sound. Have it inspected by a qualified professional
chimney sweep, a mason, or your Vermont Castings’
Authorized Dealer before the WinterWarm is installed.
Any deterioration (cracks, loose mortar or loose bricks)
must be repaired.
The fireplace should not be modified to install the
WinterWarm without first checking with your local
building inspector or fire marshal. Do not remove bricks
or mortar that may jeopardize the compliance of the
fireplace with local building codes.
Requirements of your
Existing Masonry Chimney
Your fireplace chimney must be well-constructed and
must meet minimum code requirements. The chimney
flue should have a code-approved liner made of ma-
sonry or pre-cast refractory tiles, straight or flexible
stainless steel pipe, or a poured-in-place liner. An
unlined chimney must be relined professionally. Chim-
ney height should be no less than 15’ (4.6m) above the
hearth and no more than 35’ (10.7m).
The chimney must have a nominal flue size of 8" x 8"
(203 x 203mm) or larger, with a maximum size of 12" x
12" (305 x 305mm). Some chimneys originally designed
for fireplace use may perform differently when used to
vent an air-controlled appliance such as your Winter-
Warm. A chimney on an outside wall with a large flue,
for example, may not heat up enough to sustain an
adequate draft. Such a flue can often be improved if it
is relined to reduce its size and/or insulated to keep it
warmer.
The chimney should extend at least 3’ (914mm) above
the highest point where it passes through a roof, and at
least 2’ (610mm) higher than any portion of a building
within 10’ (3m). (Fig. 18)
Existing masonry fireplace chimneys, especially older
ones, may have one or more openings used at an
earlier time to connect stoves in different rooms to the
fireplace chimney. These openings must be sealed
with masonry to the thickness of the chimney wall.
Unused openings sealed with pie plates or wallpaper
are a hazard. In the event of a chimney fire, flames
and smoke may be forced out of these unused open-
ings.
Do not connect your WinterWarm fireplace insert to
a chimney flue serving another appliance.
Minimum Fireplace Dimensions
The WinterWarm Fireplace Insert will fit most masonry
fireplaces. To confirm that it will fit yours, measure the
lintel depth, plus the height, width, and depth of your
fireplace and your hearth. Compare them to the mea-
surements in the accompanying chart. If you choose to
install a new hearth over an existing fireplace hearth,
be sure to take its thickness into consideration when
measuring both front and back height of the fireplace.
2’ Min.
2’ Min.
3’
Min.
0 To 10’
3’
Min.
0 To 10’
Reference
Point
AC617
Fig. 18 The 2’3’10’ rule for chimneys.
