9. Boilers are shipped from the factory with the primary
air shutters on the main burner wide open. It is recom-
mended these air shutters be left in the wide open posi-
tion unless there is lifting of the flame above the burner
ports. If there is lifting, the air shutters should be gradu-
ally closed until the lifting is eliminated. It may also be
necessary to adjust the primary air shutters if the input
rate is reduced by a change in the orifices.
10. After burner has been in operation for about 10 min-
utes, check gas input rate to boiler as follows:
a. Make sure that all appliances served by the gas
meter are turned off during timing of gas input rate to
the boiler.
b. Measure the time in seconds that it takes for the boil-
er to use10 cubic feet of gas. Divide 36,000 by the
number of seconds, this is the number of cubic feet of
gas used per hour. Multiply this figure by the heating
value of the gas to obtain the input in Btu per hour.
Example: An HC-125E boiler takes 4 minutes, 54 sec-
onds to use 10 cubic feet of natural gas. Local utility
indicated heating value of the natural gas being supplied
is 1020 Btu/cu ft. Therefore:
54 + (4x60) = 294 seconds
36,000
x 1020 = 124,898 Btu/hr
294
Therefore, the boiler input is correct.
NOTE: Before calculating the input of the heating
equipment, obtain the heating value of the gas from
the local utility.
11. If boiler input needs to be corrected, adjust the combi-
nation gas valve pressure regulator. Regulator is factory set
at 3.5" W.C. for natural gas or 10" W.C. for propane. Turn
adjusting screw clockwise to increase gas flow, increase
input. Turn adjusting screw counterclockwise to decrease
gas flow (decrease input). In no case, should final manifold
pressure setting vary more than .2" from factory-set
pressures. If rated input cannot be obtained with regulator
adjustment, gas supply pressure or orifice size may be the
cause. Consult your local utility and Hydrotherm.
12. The gas burner orifices supplied with the boiler have
been carefully designed to provide the correct gas input
rate for most gas conditions typically found in the U.S.
Occasionally, however, the local gas characteristics may
not allow the unit to be properly adjusted for input. If this is
the case, the local utility or Hydrotherm may recommend
the orifices be changed. When changing orifices, follow
the procedures in the Maintenance Section of this manual.
13. Start and stop burners several times by raising and
lowering the thermostat setting.
14. After the boiler has been firing long enough to raise
the boiler water temperature to above the minimum
setting of the high limit, check the high limit by turning its
setting from maximum to minimum setting. This should
turn the boiler off. Return high limit to desired setting.
15. Check boiler safety shut-off controls.
a. For boilers with standing pilot, with boiler firing,
disconnect thermocouple lead from the valve. The
valve should close.
b. For boilers with intermittent pilot, with boiler firing, dis-
connect wire connection to the "PV" terminal on Hon-
eywell S8600 control. The gas valve should close.
16
YELLOW
FLAME
(TOO LITTLE AIR)
YELLOW
TIPPING
(MARGINAL)
LIFTING
(TOO MUCH AIR)
NORMAL
(HARD FLAME)
NORMAL PILOT FLAME
MAIN BURNER FLAMES
Q314A/Q309A
CONSTANT PILOT
MODELS
Q345A
INTERMITTENT
IGNITION PILOT
MODELS
FIGURE 2.3
Summary of Contents for EW2-1203
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