Crown Boiler BWF061 User Manual
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3) Vacuum Switch – This boiler is equipped with a vacuum switch that is designed to prevent burner operation if the
combustion fan does not operate properly or there is a blockage in the vent system. This switch “makes” (permits
burner operation) as the vacuum increases. Figure 40 shows the correct method of reading the switch vacuum. The
vacuums in Table 9 are the minimums required for reliable operation. After the boiler fires, the vacuum will drop for
several minutes before stabilizing. The vacuum shown under “Burners On” in Table 9 is the minimum reading which
should be observed after the vacuum has stabilized. The Table 9 readings correspond to sea level vacuum switch
settings. Consult your Crown representative for possible variations in settings at altitudes over 2000ft.
MODELS
BURNERS ON
BWF061, BWF095
-0.57
-0.51
BWF128, BWF162
-0.96
-0.89
BWF195, BWF229
-1.21
-1.14
TABLE 9: MINIMUM. VACUUM SWITCH
READINGS (in. W.C.)
DURING
PREPURGE