percent. Check to insure minimum negative .02 W.C., (water column), “overfire” draft and
zero (0) smoke. If - .02 W.C. “overfire” draft can not be maintained, changes and/or
modifications may be required in the venting or the chimney.
The following table is provided as a guideline for initial start-up. Final adjustments
MUST
be made using combustion instruments as previously mentioned.
MODEL
END
STATIC
AIR
AIR
NOZZLE
NO.
CONE
DISC
BAND
SHUTTER
FURNISHED
SETTING
SETTING
OBC3D
F-0
2-3/4
0
8
.65X80B
OBC3
F-3
2-3/4
1
8
.85X80B
OBC4D
F-3
2-3/4
1
8
.85X80B
OBC4
F-6
2-3/4
3
10
1.25X80B
Information in above table uses Beckett model AF burner for both model numbers OBC-
3 and OBC-4.
OBC3D and OBC4D are derated boilers which require derate kits; part numbers 5612206
for OBC3D and 5612209 for OBC4D.
CHECK SAFETY CONTROL CIRCUIT after burner adjustments have been made for
satisfactory performance.
A. High limit control: remove cover and note temperature setting. See figure 17 on page
16. With the burner operating, decrease this setting to the minimum point. When boiler
water temperature exceeds this set point, the high limit switch will open, shutting off the
power to the oil burner. Return setting to desired high limit point. Burner should re-start.
B. Primary control and flame sensor:
To Check:
A. Flame failure - simulate by shutting off oil supply with hand valve while burner is on.
Sixty seconds after flameout, the safety switch locks out, ignition stops, motor stops and oil
valve - when used - closes. To restart, open oil supply valve and reset safety switch.
B. Ignition failure - with burner off, close oil supply valve and run through start-up
procedure, The safety switch should lock out as in flame failure.
C. Power failure - Turn off main power supply switch while burner is operating. When
burner stops, restore power and burner should start.
If operation is not as described as above, check wiring and controls.
PREVENTIVE MAINTENANCE of an oil fired boiler reduces operating costs. The boiler,
vent and vent pipe should be inspected for accumulation of soot or scale deposits
periodically but at least once every year before the start of each heating season. When soot
is present on the section walls and flueways, improper combustion will result, causing
additional sooting and scaling until flueways are completely closed. To remove soot and
scale from the flueways, remove top jacket panel, top clean-out plate and burner. See
instructions on page 15 for instructions on removal of the oil burner. Using a wire brush,
brush the soot and scale into the combustion chamber where it can be removed through
PAGE 14
