Installation guide

E. Adjustment of Electrodes. Adjust ignition
electrodes according to burner manufacturer's
instructions to assure prompt ignition.
F. Operate Burner. Operate burner, adjust air
setting for good flame by visual inspection,
and run for at least 10 minutes or until
operation has stabilized.
G. Check Pump Pressure. Bleed air from pump
and supply piping. Check pump pressure and
adjust to I00 psig, if necessary (or to
manufacturer's specification).
2. COMBUSTION ADJUSTMENT STEPS
H. Set Draft. Check the draft reading over the
fire with a draft gauge through a 1/4" hole
drilled in the fire door or inspection door.
(This hole should be in the inspection door for
oil-fired matched units, and in the fire door
for conversion installations. If possible, the
hole should be above the flame level.) Adjust
the barometric draft regulator on the flue to
obtain the overfire draft recommended by the
manufacturer. If no such recommendations are
available, set overfire draft to assure a
negative pressure within the combustion
chamber (usually -.02 inches W.C.).
With some equipment, it will not be possible
to take draft readings over the fire. In this
case, adjust the draft regulator to give a
breech draft reading between -.04 and -.06
inches W:C., taken at the sampling hole.
Seal draft or sampling hole in inspection or
fire door after these tests have been made,
using a plug, bolt, or high temperature sealant.
Some appliances are designed for positive
pressure firing. Follow the manufacturer's
recommended performance specifications for
draft levels and venting requirements.
I. Check Smoke Readings. After burner has
teen operating 5 or 10 minutes, take a smoke
measurement in the flue, following the smoke
tester instructions. Oily or yellow smoke spots
on the filter paper are usually a sign of
unburned fuel, indicating very poor combus-
J!
tion, which could possibly produce high
emissions of carbon monoxide and unburned
hydrocarbons. When retrofitting in older
appliances, this condition can sometimes be
caused by too much air, or by other factors, if
this condition cannot be corrected, major
renovation or even equipment replacement
may be necessary.
Adjust Air Setting.
(1) Set the burner air controls to obtain a
trace of smoke at steady state operation.
Remember, as the excess air is reduced,
the percent of 0 2 decreases and the
percent of CO 2 increases. By increasing
the excess air, we lower the CO 2 percent
and raise the 0 2 percent. The relationship
between CO 2, 0 2, and excess air is shown
in Figure 61. The levels most frequently
encountered in oil burner servicing are in
bold face.
(2) At the trace level, measure the CO 2 or 0 2.
This is typically around 13% CO 2 / 3.3%
02 . (See Figure 62.) Now, increase the
air setting until the CO 2 is reduced by 1 to
2 percentage points from a trace of smoke,
or the 0 2 is increased by about 2 to 3
percentage points.
(3) Make a smoke test. It should be zero. You
have built in a margin to accommodate
v_ables that could be encountered during
the heating season.
(4) Lock the air adjustment and repeat draft,
CO2/O 2, and smoke measurements to
make sure the setting has not shifted.
16 f 1
Typioa,
I_ Adjustment[ I
RGURE 62 Typicalsmoke vs. CO2 percent
46