F - Adjusting Gas Input Rate - Burnham ES2 ES2 Installation & Service Instructions Manual

Natural Gas Boilers:
Turn off gas supply to all appliances other
1.
than gas-fired boiler.
Note the rated manifold gas pressure listed
2.
on the boiler's rating label.
Connect Manometer to manifold pressure
3.
tapping on Gas Valve (Figure F-1).
F-1
Light main burners by adjusting thermostat
4.
to highest setting.
If required, adjust gas manifold pressure to
5.
the rated setting by turning the gas valves
adjustment screw clockwise to decrease
manifold pressure or counterclockwise to
increase manifold pressure (Figure F-2).
Several turns may be required.
Do not force the adjustment screw.
On models using more than one gas valve,
6.
turn "off" the gas valve not having pilot
control and first adjust the gas valve with
pilot control. Then, turn "on" both gas valves
and adjust the gas valve without pilot control.
Clock gas meter for at least two (2)
7.
revolutions of the dial typically labeled ½ or
1 cubic foot per revolution on a residential
gas meter.
44
APPENDIX F – ADjUSTING GAS INPUT RATE
F-2
Determine gas flow rate in Cubic Feet
8.
per Hour based on elapsed time for two
revolutions. (Example: 70 Seconds for (2)
Revolutions = 102.8 Cu. Ft.
When the clocked time falls between two
9.
table values (Table F-1), add the table
values shown above and below your clocked
reading and divide by 2 (Example: 68
Seconds for (2) Revolutions = (110.7+102.8)
/2 = 106.7 Cu. Ft./Hr.).
Obtain gas-heating value (Btu per cubic
10.
foot) from gas supplier or use nominal
value of 1000 Btu per cubic foot.
Multiply gas flow rate by gas heating value.
11.
(Example: 70 Seconds for (2) Revolutions
= 120.8 Cu. Ft./Hr. X 1027 Btu/Cu. Ft. =
124,061 Btu/ Hr.
Compare measured input rate to input rate
12.
stated on rating label.
DO NOT EXCEED the boiler's rated gas
input.
If input is too high, reduce input rate by
13.
decreasing manifold pressure. Do not
reduce more than 0.3" w.c. Instead, contact
Burnham for an orifice replacement kit.
If input is below 98% of Rating Label input,
14.
increase manifold gas pressure no more
than 0.3 inches w.c. If measured rate is still
less than 98% of rated input, replace or re-
drill existing main burner gas orifices: