CFM Corporation WMC36 WMC42 manual Installing Outside Air Kit, Installing the Chimney System

Installing Outside Air Kit

An outside air kit is installed in all WMC Series Fire- places. If desired, or if local codes mandate the use of an air kit, then an AK-MST is required to complete the installation (from air kit to the outdoors). If the outside air kit is to be used, the AK-MST MUST be installed BEFORE the fireplace is enclosed. Refer to the AK- MST instructions for field installation. The outside air control lever is located at the front edge of the left side brick. To ‘open’, push the control lever down toward the hearth brick. To ‘close’, pull the control lever up and over. (Fig. 16)

WMC Series Woodburning Fireplace

Inner Pipe Section

Pipe

Rim

UP

Hem

Lance

Pipe

Rim

CLOSED

OPEN

FP710

Fig. 16 Outside air operation.

Installing the Chimney System

Start by attaching the first chimney section to the collar on top of the fireplace.

Install the pipe as pictured in Figure 17. When you get a good lock, you will hear the pipe clearly snap together. Once sections are snap-locked in place, it is extremely difficult to get them apart. Make sure the pipe is firmly snapped and locked together as each pipe section is mounted.

When installing elbows, only outer pipe will snap- lock. Middle pipes simply slide into position. Be sure to always attach straps on upper elbow to a structural framing member. (Fig. 18)

Continue installing the pipe as required until pipe is installed up through the ceiling. At this point, you must install a firestop spacer.

Installing the Firestop Spacer

in the Ceiling Hole

A firestop spacer is used to keep pipe spaced properly and required for safety.

Nail the firestop spacer (at each corner) to the framing members of the ceiling hole. NOTE: A firestop spacer is not required at the roof.

FPC558

Fig. 17 Install pipe, listening for the snap-lock to fasten.
Elbow Strap	Support Structure

	Elbow Strap
	(Must be tight)
	Ceiling
	Hole
Angled Strap	Framing
	Angle Firestop
	Chimney Support Strap
FP270/271	(Must be tight)

Fig. 18 Attach straps to a structural framing member.

Hole sizes listed in Figure 13 for angled firestop spacers provide minimum required air space to chimney pipe for ceiling thickness up to 8" (203 mm). When combined thickness of ceiling material, ceiling joists and flooring material exceeds 8" (203 mm), adjustments must be made in framing to assure that minimum air spaces to

chimney are maintained.

Proper Firestop Spacer Installation

Figure 19 shows different installation procedures for both an area that is an attic and an area that is not an attic.

If the area above the ceiling is not an attic, position the firestop spacer with the flange on the ceiling side and the angled portion extending up into the hole.

If the area above the ceiling is an attic, position the firestop spacer with the flange on the top of the framed

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