Bradford White Brute BNTH Installation And Operation Instructions Manual page 62

Page 58
wire from the electrode. Remove the two bolts fastening
the electrode to the burner doors. Remove and replace
the old flame sensor gasket. If the old electrode is
determined to be defective, install a new flame sensor
electrode in the reverse order.
The ignitor and sensor may be hot, and can cause
burns or injury.
Transformer with Integral Circuit Breaker
The appliance has a 24Vac transformer with integral
4 amp circuit breaker installed to supply the control
voltage required for the appliance. The transformer
is sized to provide power for the Brute unit only, and
should not be used to supply power to additional field
devices. If additional loads are added, or a short occurs
during installation, the integral circuit breaker may trip. If
this happens, be sure to reset the circuit breaker before
replacing the transformer.
The transformer is mounted underneath the control
panel. If the transformer must be replaced, turn off the
120Vac power to the appliance. Remove the transformer
wires from the terminal blocks. Remove the fasteners
holding the transformer, then remove the transformer.
Replace with a new transformer in the reverse order.
If the transformer is replaced with a part other than the
OEM transformer, be sure to add circuit protection if it is
not integral to the new transformer.
Failure to include proper circuit protection may lead to
premature component failure, fire, injury or death.
Blower
The combustion air blower is a high-pressure centrifugal
blower with a variable speed motor. The speed of the
motor is determined by the control logic. 120 Volt power
remains on to the blower at all times. If the blower
must be changed, turn off the 120 Volt power and gas
supply to the unit. Take the front panel off. Disconnect
the 120 Volt and control signal connections from the
blower. Disconnect the bolts connecting the Venturi to
the blower housing. Disconnect the fan outlet bolts from
the burner door blower arm. If the fan is determined to
be defective, replace the existing fan with a new one,
reversing the steps listed above. Be sure to install all of
the required O-rings and gaskets between the blower
arm and the blower and blower face and venturi flange.
Heat Exchanger Coils
Black carbon soot buildup on the heat exchanger is
Caution
WARNING
caused by one or more of the following; incomplete
combustion, combustion air problems, venting problems,
or heater short cycling. Soot buildup or other debris on
the heat exchanger may restrict the flue passages.
If black carbon soot buildup on the heat exchanger is
suspected, disconnect the electrical supply to the unit,
and turn off the gas supply by closing the manual gas
valve on the unit. Access the heat exchanger through
the burner door at the front of the boiler, and inspect the
tubing using a flashlight. If there is a buildup of black
carbon soot or other debris on the heat exchanger, clean
using this procedure:
Black carbon soot buildup on a dirty heat exchanger
can be ignited by a random spark or flame. To prevent
this from happening, dampen the soot deposits with
a wet brush or fine water spray before servicing the
heat exchanger.
1. Shut off the 120 Volt power supply to the boiler
2. Turn off all manual gas valves connecting the
boiler to the main gas supply line.
3. For BNT 600 models only:
(All other sizes please skip to step four)
BNT 600 models will require the gas valve to be
removed in order to remove the burner door. To do
this, remove the wiring connections from the gas
valve. Remove the flange bolts from the gas supply
pipe connected to the gas valve (1B). Remove the
flange bolts connecting the gas train to the Venturi
(1A). Remove the gas train assembly, and keep
the gaskets and O-rings.
4. Remove the four bolts connecting the blower
flange to the burner door arm.
5. Remove the nuts located on the outside diameter
of the burner door to the heat exchanger.
6. Remove the burner door and burner assembly
from the heat exchanger.
7. Disconnect the condensate drain line.
8. Attach a longer hose to the drain and run it to a
bucket.
9. Clean the heat exchanger by brushing away any
light accumulations of soot and debris. Use a brush
with soft bristles (non metallic) to avoid damaging
the surfaces of the heat exchanger tubes.
10. Once the tubes have been brushed clean, rinse
the tubes and combustion chamber with a small
amount of water to rinse all of the debris out of
the bottom of the flue collector and into the longer
condensate trap line. This will be diverted into the
separate container.
B W
RADFORD
WARNING
HITE