4
INSTALLING THE BURNER: FLANGE MOUNTED
1. Measure, in the burner opening, the distance from the
inside of the combustion chamber to the outside of the
mounting plate to find the insertion length of air tube
needed. Position flange with sleeve inside on air tube
at a point from end of burner corresponding to this
measurement. Tighten set screws to anchor flange. The
flange is now located so that the end of the burner will
be flush, or almost flush, with the inside of the combus-
tion chamber.
2. Slide the end of the air tube into the opening and secure
the flange to the front plate.
FIG. 2
Brick combustion chamber, side view.
FIG. 3
Wet leg boiler. No combustion chamber, side view.
FIG. 4
Scotch Marine boiler. No combustion chamber.
INSTALLING THE BURNER: PEDESTAL MOUNTED
1. Adjust the pedestal so that the height of the air tube
matches the location of the burner opening.
2. Slide the end of the air tube into the opening so that it is
flush or nearly flush with the inside ofthe combustion cham-
ber.
3. From the outside of the unit, seal the space around the air
tube with refractory cement or equivalent.
FIG. 5
FIG. 6
HOW TO ADJUST THE COMBUSTION HEAD
The retention ring position ahead of the throttle ring is
adjustable from zero (flush) to 1
1
⁄
4
inches (Dimension “A”
Figs. 7 and 8). Turning the adjusting screw in (clockwise)
increases the distance “A“ ahead. This distance is indi-
cated by lifting the housing cover and reading the scale on
the nozzle line across the corners on sides of the channel
guiding the nozzle line. Each division is
1
⁄
16
inch.
Refer to “A” dimension given in Table 5 and 6 for cor-
responding nozzle selection. (If alternate nozzle sizes are
used select “A” dimension from the high fire oil delivery
rate. Column 5). EXAMPLE: 70lCRD firing at 11.40 GPH
high fire. “A” column setting reads
1
⁄
4
".
1. Turn adjusting screw counterclockwise until zero on
scale is aligned with rear of housing (“A” equals zero see
Fig. 8).
2. Now turn adjusting screw clockwise until the ‘/J’ gradu-
ation on the scale coincides with rear of housing. Each
mark (or line) is
1
⁄
16
inch. (See Fig. 8).
3. The retention ring will now be exactly
1
⁄
4
" ahead of the
throttle ring. (See “A” dimension. Fig. 7).
CAUTION: Housing coxer should be raised slightly when
attempting to change retention ring setting (“A” dimension)
otherwise scale will be torn or distorted. This can be done
by backing out the two hold-down screws 2 to 3 turns. and
then lifting cover slightly while adjusting. Be sure to tighten
screws after adjusting.
FIG. 7
FIG. 8
COMBUSTION HEAD ADJUSTMENT FOR
COMBUSTION AIR
When adjusting the combustion head forward or back, the
space around the rim ofthe retention ring is increased or
decreased which increases or decreases the amount of
combustion air to correspond with the nozzle sizes used.
Also, by using the specified nozzle combinations for low
and high fire (Tables 5 and 6), the air fuel ratio for both
low and high fire are optimized by the automatic damper
motor and its associated linkage. THIS LINKAGE HAS
BEEN PRE-SET AT THE FACTORY AND SHOULD NOT BE
ADJUSTED. It is set to be in the fully open position when
the burner is in high fire.
By adjusting the combustion head according to Tables 5
and 6 (last column), for the firing rate delivered by the par-
ticular nozzles, the burner should deliver very close to the
proper amount of combustion air and CO
2
. Slight increases
or decreases will usually be required depending upon the
draft. Normally a draft of 0.02 to 0.04 inches W.C. (nega-
tive pressure) is recommended over the fire for natural draft
applications.
Model 701CRD is provided with a low fire air shutter ad-
justing screw. This adjustment limits the amount of shutter