Bradford-White Corp BNTV Water Heater User Manual


 
BRADFORD WHITE CORP.
Page 44
in Table 16. If the CO
2
is not within the range
shown, adjustments may be made. To adjust the
low fire CO
2
, locate the low fire adjuster screw
according to the appropriate figure. Slowly make
adjustments in 1/16 of a revolution increments
until the CO
2
is within the range identified.
4. Repeat steps 2 and 3 to confirm that the CO
2
ranges are within the required ranges. Adjust if
necessary.
5. Confirm that the differential pressure is still within
the appropriate range.
6. If any of the measurements cannot be adjusted
to the specified ranges or the CO levels are
above 150ppm when adjusted please consult the
factory for further information.
7. Remove the differential pressure gauge from the
air and gas pressure taps making sure to close all
ports after the gauge has been removed.
WARNING
Improper adjustment may lead to poor combustion
quality, increasing the amount of carbon monoxide
produced. Excessive carbon monoxide levels may
lead to personal injury or death.
GAS TYPE HIGH FIRE, CO
2
LOW FIRE, CO
2
DIFFERENTIAL
PRESSURE
Natural 9.0 to 8.8%
0.5% lower than -.005 to
Propane 10.0 to 9.8%
high fire setting -.015" wc
Table 16. CO
2
Range and Pressure Differential.
label and turn on gas and electrical power to
appliance.
4. Brute Elite will enter the start sequence. Blower
and pump will energize for pre-purge, then the
ignition sequence starts. After all safety devices
are verified, the gas valve opens. If ignition
doesn’t occur, turn off the Brute Elite, check that
there is proper gas supply. Wait 5 minutes and
start the unit again.
5. Turn Brute Elite on.
6. After placing the appliance in operation, the
Burner Safety Shutoff Device must be tested:
(a) Close gas shutoff valve with burner operating.
(b) Flame will go out and blower will continue to
run for the post purge cycle. One or three
additional attempts to light will follow
including pre-purge, ignitor on, valve/flame on
and post purge. Ignition will not occur as the
gas is off. The ignition control will lockout.
(c) Open gas shutoff valve. Reset the boiler
control by pressing the
RESET button on the
control or on the display. Restart the
appliance. The ignition sequence will start
again and the burner will start. The appliance
will return to its previous mode of operation.
Caution
Should any odor of gas be detected, or if the gas
burner does not appear to be functioning in a normal
manner, CLOSE MAIN SHUTOFF VALVE. Do not
shut off switch. Contact your heating contractor, gas
company, or factory representative.
10.2.2 Boiler Setup and Adjustment
1. Connect a manometer capable of reading 0.01"wc
to the gas valve locations shown in Figure 33. The
positive side of the manometer should be
connected to the location labeled “air pressure
tap.” The negative side of the manometer should
be connected to the location labeled "gas pressure
tap." This differential pressure should be slightly
negative (see Table 16).
2. Measure the CO
2
/O
2
in the flue products at high
fire. The Brute Elite can be forced to high fire to
allow for easier setup. Refer to Section 8.1, Table
14 for instructions on how to access the forced rate
menu. The CO
2
readings should be between the
values shown in Table 16. If the CO
2
is not within the
range shown, adjustments may be made. To adjust
the high fire CO
2
, locate the high fire adjuster screw
according to the appropriate figure. Slowly make
adjustments in 1/16 of a revolution increments until
the CO
2
is within the range identified.
3. Measure the CO
2
/O
2
in the flue products at low
fire. Brute Elite can be forced to low fire to allow
for easier setup. Refer to Section 8.1, Table 14 for
instructions on how to access the forced rate menu.
CO
2
readings should be between the values shown
10.3 Shutting Down Brute Elite
1. Turn off the main electrical disconnect switch.
2. Close all manual gas valves.
3. If freezing is anticipated, drain Brute Elite and be
sure to also protect building piping from freezing.
All water must be removed from heat exchanger or
damage from freezing may occur.
This step to be performed by a qualified service person.
10.4 To Restart Brute Elite
If drained, follow Section 10.1 in this manual
for proper filling and purging.
1. Turn off the main electrical disconnect switch.
2. Close all manual gas valves.
3. WAIT FIVE (5) MINUTES.
4. Set the aquastat or thermostat to its lowest setting.
5. Open all manual gas valves.
6. Reset all safety switches (pressure switch, manual
reset high limit, etc.).
7. Set the temperature controller to the desired
temperature setting and switch on electrical power.
8. Burner will go through a prepurge period and
ignitor warm-up period, followed by ignition.