Starting and Operating Instructions
4-2
750-96 (revised 2010)
Model CB Packaged Boiler Manual
Before operating the boiler feed pump or the oil supply pump, be sure all valves in the line are open or properly
positioned.
For safety’s sake, make a final pre-startup inspection, especially checking for any loose or incomplete piping or
wiring or any other situations that might present a hazard.
4.2 — Control Settings: Steam and Hot Water
See Chapter 5 for adjustment instructions for the following controls.
Inspect operating limit control for proper setting:
1. The pressure control of a steam boiler should be set slightly above the highest desired steam pressure, but at
least 10% lower than the setting of the safety valve.
2. The temperature control on a hot water boiler should be set slightly above the highest desired water tempera-
ture and within the limits of the pressure vessel.
Inspect the high limit control for proper setting:
1. On a high pressure steam boiler, this should be set approximately 10 lbs. above the operating limit pressure
control setting, if feasible, or midway between operating limit pressure and safety valve setting. The setting on
a low pressure steam boiler may be 2 or 3 lbs. above the operating limit setting but must exceed valve setting.
2. On a hot water boiler, the temperature control should be 5º - 10º above the operating limit temperature control
setting.
Inspect the modulating control for proper setting. This control must be set and adjusted so that the modulating
motor returns to low fire position before the operating limit control opens. It is further desirable to have its low
point setting somewhat below the cut-in setting of the limit control so that the burner operates in low fire position
for a brief period on each start rather than immediately driving to a high fire position.
Inspect the low water cutoff and pump control as well as the auxiliary low water cutoff (if equipped, optional). Nor-
mally, no adjustment is required since these controls are pre-set by the original manufacturer. Check for freedom
of float movement. Float movement can be verified by observing the level of water in the gauge glass when the
water supply has been cut off either by the stopping of the feed pump or by the closing of a valve, and the restart-
ing of the pump or opening of the valve when water is drained from the pressure vessel. The importance of proper
functioning of low water controls cannot be over emphasized. Make sure that the control and the piping is plumb.
The settings of controls relating to fuel, either oil or gas, are cover in subsequent sections.
In the event the boiler is equipped with optional control devices not listed here, be certain to ascertain that their
settings are correct. If additional information is required, see your Cleaver-Brooks representative.
NOTE: The settings of all the above controls may require some readjustment after the boiler is started and running for
a short period. The scale settings on the controls are relatively accurate, but are principally for use as guides. Final
adjustment should be based on and agree with the reading of the steam pressure gauge or the water temperature
gauge.
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