Service manual

SC Series Boilers – Installation and Service Manual
17
3.3 CHECK BURNER SYSTEM
To maintain safe and efficient operation, examine the burner system regularly through the inspection
window in the front of the boiler behind the door.
Check condition of burner system
It is possible for parts of the burners system to
become plugged, cracked, eroded and/or
dislodged resulting in unsafe operation.
Check for lifting
Flames should not lift excessively from the
burner ports. The flames may lift slightly during
ignition or when the burners are cold.
Check ignition and extinction
Ignition should flow quickly and smoothly across
all the burners. Popping noises or explosions
from the burners during ignition, extinction or
abnormal burner operation indicates the need
for service.
Check flame color
An extremely yellow flame, as seen on a burning
candle or match, is an indication of incomplete
combustion and is usually accompanied by the
formation of soot and carbon monoxide (carbon
monoxide is a lethal, colorless and odorless
gas). If soot is allowed to accumulate, it will
partially restrict free passage of products of
combustion to the flue. Under typical operating
conditions, the flame should have a distinct
bright blue inner cone and a blue/light orange
outer cone.
If any of the above problems are observed or the burner system does not operate properly,
immediately take corrective measures following in section 1.1 and 1.3.
3.4 AQUASTAT ADJUSTMENT
The factory mounted aquastat controls main burner firing by sensing outlet water temperature. To set the
temperature of this control, adjust the dial until indicator points to the temperature (setpoint) at which the
gas valve will close. The gas valve will open at setpoint less the differential. The automatic reset safety
high-limit aquastat is either fixed or, if adjustable, should be set a minimum of 20°F (10°C) above the
setting of the aquastat.