Controllers; Ignitor Assembly; Flame Sensor; Transformer With Integral Circuit Breaker - Bradford White LAARS NEOTHERM LC NTH1000 Installation And Operation Instructions Manual

NeoTherm LC Boilers and Water Heaters
to the gas valve. Remove the electrical connections
to the gas valve. Remove the bolts connecting the
Venturi flange to the blower. This allows the entire
gas valve/Venturi assembly to be removed as an
assembly to facilitate inspection and cleaning.
After the valve has been removed, reassemble in
reverse order making sure to include all gaskets and
O-rings. Turn on the manual gas valves and check
for gas leaks. Turn on the 120 Volt power. Place the
unit in operation following the instructions in Section
10. Once the boiler is operating, check for leaks
again and confirm all fasteners are tight.
Check the setup for the unit according to the
instructions in Section 9.
11.B.3 Controllers
Each unit has two integrated controllers that
incorporate manual reset high limit control, operating
temperature control, modulating control, ignition
control, outdoor reset control, pump control and
many other features. If any of these features are
thought to be defective, please consult the factory for
proper troubleshooting practices before replacing a
control.
If it is necessary to replace a controller, turn off
all power to the unit and shut off all manual gas
valves to the unit. Remove the front door to the
unit and the control panel plastic bezel. Remove
all wire connections from the control board. The
control board connections are keyed to only allow
connection in the proper location, but proper
handling techniques should be used to avoid
damage to the wiring or connectors. To remove the
control, undo the mounting screws. To replace the
control repeat the steps listed above in the reverse
order making sure to connect all wires in the proper
locations. Place the unit in operation following the
steps outlined in Section 10.
11.B.4 Ignitor Assembly
The ignitor assembly is a two rod system that
consists of a ground rod and a sense rod. To
remove the ignitor assembly, shut off the 120 Volt
power supply to the unit. Turn off all manual gas
valves connecting the unit to the main gas supply
line. Remove the front door of the boiler to gain
access to the ignitor assembly. Remove the two
wires connected to the assembly. Then remove the
two bolts connecting the ignitor assembly to the
burner door. Remove and replace the old ignitor
assembly gasket. If the old assembly is determined
to be defective, install a new ignitor assembly in the
reverse order. Replace the gasket if necessary.
11.B.5 Flame Sensor
The flame sensor is a single rod system. To replace
the flame sensor electrode, shut off the 120 Volt
power supply to the boiler. Turn off all manual gas
valves connecting the boiler to the main gas supply
line. Remove the front door of the boiler to gain
access to the flame sensor electrode. Remove the
flame sensor 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,
reinstall a new flame sensor electrode in the reverse
order.
The igniters and sensors can become very hot.
If you touch these parts accidentally, this can
cause burns or injury.
11.B.6 Transformer with Integral Circuit
Breaker
The appliance has a 24 VAC transformer with
integral 4 amp circuit breaker installed for supplying
the control voltage required for the unit only. The
transformer is sized for the load produced by the
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.
If the transformer must be replaced, turn off the 120
VAC power to the unit. Remove the transformer
wires from the terminal blocks. Remove the
fasteners holding the transformer, and remove the
transformer. Replace with a new transformer in
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.
WARNING
Failure to include proper circuit protection may
lead to premature component failure, fire, injury
or death.
11.B.7 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 Volts are supplied to the blower at all
times.
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Caution