page 3 of 8
COLLAR INSTALLATION
This control is shipped with a collar patterned to fi t a single wall round
vent pipe. To attach this collar to the fl ue, See Figure 4 and follow the
instructions below.
1. Bend outward the two ears at the front corners of the collar. Bend
90 degrees,
1
⁄
4
" behind the single hole on the straps.
2. Insert clamping screw in ears on collar and bolt the remainder of
the collar together.
3. Hold the collar against the side of the fl ue in the exact position it is
to be installed (shown by dotted lines) and mark the outline of the
collar on the fl ue.
4. Cut a hole in the fl ue about
1
⁄
2
" inside of this outline.
5. Make a series of cuts about
1
⁄
2
" apart from the edge of this hole to the outline marks.
6. Strap the collar to the fl ue pipe.
7. Bend the tabs formed by the series of cuts outward against the inside of the collar to make a tight joint.
8. Insert the draft control. (See Draft Control Installation and Adjustment Section.)
DRAFT CONTROL INSTALLATION AND ADJUSTMENT
1. Insert the draft control into the collar or tee. The front face of
the control MUST be plumb and the bearing surfaces MUST
be level whether the control is on a horizontal, vertical or
sloping fl ue pipe.
2. Use a spirit level and level accurately. (See Figure 5) Secure
the control in the collar by tightening the clamping screws. If
a tee is used or a collar is supplied locally, the control may
be held in place by sheet metal screws.
DRAFT CONTROL INSTALLATION IN TYPE B VENT PIPE
CAUTION: DO NOT use the supplied collar when mounting draft control to Type B Vent Pipe. Install by using a
Type B Vent Pipe Tee.
1. Install a vent pipe reducer or increaser into the inner pipe and fasten using sheet metal screws. (See Figure 5)
2. The opening of the Type B Vent Tee, at the draft control
mounting location, should be sealed with a high
temperature sealant or equivalent.
3. Refer to Draft Control Installation Section.
WHAT DRAFT SETTING TO USE
When adjusting the control, two things are essential;
1. The burner must be operating for at least 10 minutes to obtain
maximum chimney draft.
2. An analysis of the fl ue gases is necessary to determine the
percentage of CO
2
and check for presence of CO.
ADJUSTING THE DRAFT CONTROL WITH 4” MG1
The control MUST be adjusted to the desired draft setting by
adding or removing the washer-type weights supported by the
two chains on the side of the draft control. (See Figure 6) DO
NOT move the weight attached directly to the gate, this is used
only for balancing at the factory.
Figure 4
Figure 5
Figure 6
Refer to the appliance instructions and/or to the local gas company for the proper CO
2
readings and allowable
CO levels. A rule of thumb for draft setting is between .01” to .03” of water column draft at the appliance outlet.
(Check equipment requirement.)
Changes in the adjustment of the 4” MG1 control should be made by adding or removing the washer-like
weights (supplied with the control) to or from the weight holder chain assembly. After the control is adjusted,
its action will be entirely automatic, the gate will open or close by itself to correct for changes in the draft that
occur in the chimney.
P/N 46285300 Rev F 01/18
