temperature. Main burners and pilot burner should extinguish, and blower should stop.
3.Adjust limit to setting above observed temperature. Ignition sequence should begin.
4.Adjust thermostat to lowest setting. Adjust limit to desired setting.
P.Adjust gas input rate to boiler.
1.Adjust thermostat to highest setting.
2.Check manifold gas pressure. See Table 5 or rating label located in the boiler’s vestibule compartment. Adjust gas valve pressure regulator as necessary (turn adjustment screw counterclockwise to decrease manifold pressure, or clockwise to increase manifold pressure). If pressure cannot be attained, check gas valve inlet pressure. If less than minimum indicated in Table 5 or boiler’s rating label, contact gas supplier for assistance.
3.Clock gas meter for at least 30 seconds. Use Table
13 to determine gas flow rate in Cubic Feet per
Hour.
WARNING
Failure to properly adjust gas input rate will result in over firing or under firing of the appliance. Improper and unsafe boiler operation may result.
4.Determine Input Rate. Multiply gas flow rate by gas heating value.
5.Compare measured input rate to input rate stated on rating plate.
a.Boiler must not be over fired. Reduce input rate by decreasing manifold pressure. Do not reduce more than 0.3 inch w.c. If boiler is still overfired, contact your Burnham distributor or Regional
Office for replacement Gas Orifice.
b.Increase input rate if less than 98% of rating plate input. Increase manifold gas pressure no more than 0.3 inch w.c. If measured input rate is still less than 98% of rated input:
i.Remove Main Burners per procedure in Section IX: Service.
ii.Remove gas orifices. Drill one (1) drill size larger (drill size is stamped on orifice, or see
Section X: Repair Parts).
iii.Reinstall gas orifices and main burners.
Measure input rate.
6.Recheck Main Burner Flame.
7.Return other
Q.Review User’s Information Manual and system operation with owner or operator.
Table 13: Gas Flow Rate in Cubic Feet
Per Hour
Seconds | Size of Gas Meter Dial | ||
for One |
|
|
|
One | Two | ||
Revolution | Cu. Ft. | Cu. Ft. | Cu. Ft. |
30 | 60 | 120 | 240 |
32 | 56 | 113 | 225 |
34 | 53 | 106 | 212 |
36 | 50 | 100 | 200 |
38 | 47 | 95 | 189 |
40 | 45 | 90 | 180 |
42 | 43 | 86 | 172 |
44 | 41 | 82 | 164 |
46 | 39 | 78 | 157 |
48 | 37 | 75 | 150 |
50 | 36 | 72 | 144 |
52 | 35 | 69 | 138 |
54 | 33 | 67 | 133 |
56 | 32 | 64 | 129 |
58 | 31 | 62 | 124 |
60 | 30 | 60 | 120 |
45
