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MagnaTech
BOILERS AND VOLUME WATER HEATERS
with the fuel/air mixer to the unit. It is designed
to operate with gas supply pressure between
4 and 13 inches w.c.. To remove the gas valve
or fuel/air mixer, shut off the power supply
to the boiler. Turn off all manual gas valves
connecting the boiler to the main gas supply
line. Remove the front doors of the boiler, and
the top panels, to gain access to the gas valve
and fuel/air mixer. Disconnect the four flange
bolts connecting the gas manifold pipe to the
gas valve. Remove the electrical connections to
the gas valve. Remove the bolts connecting the
fuel/air mixer flange to the blower. This allows
the entire gas valve and fuel/air mixer 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
main 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.
11.2.3 Controller
Each MagnaTech has an integrated controller
that incorporates 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. Open the front doors to
the unit. 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.
11.2.4 Hot Surface Ignitor
The ignitor equipped in MagnaTech is a
silicone-nitride ceramic encased hot surface
ignitor. The silicone-nitride element is extremely
fragile and should be handled with care in the
event of removal (never touch the silicone-
nitride tip with bare skin, oils in your skin can
cause damage and failure upon heat up. To
verify a defective ignitor the cold resistance of
the wires can be measure to be in the range of
9-17 oHms if the ignitor is good, and zero oHms
would indicate a defective ignitor.
11.2.5 Flame Sensor
The flame sensor is a single rod system. The
minimum flame signal that will allow the unit
to fire is 0.8 volts. To replace the flame sensor
electrode, shut off the power supply to the
boiler. Turn off all manual gas valves connecting
the boiler to the main gas supply line. Open
the front doors of the boiler to gain access to
the flame sensor electrode. Remove the flame
sensor wire from the electrode. Remove the
two nuts fastening the electrode to the burner
plate. 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.
Caution
The igniters and sensors get become very hot.
If you touch these parts accidentally, this can
cause burns or injury.
11.2.7 Blower
The combustion air blower is a high pressure
centrifugal blower with a variable speed motor
driven by a factory installed VFD located in
the high voltage box. The speed of the motor
is determined by the controls logic which is
delivered to the VFD by a 0-10VDC signal.
Even with the unit powered up and a call for
heat off, the VFD is still supplying voltage to the
blower motor but at 0 HZ. Main Power
MUST
be disconnected before any attempt is made to
service the blower.
If it is necessary to replace or remove the
blower, turn off main power, remove hardware
that connects the Fuel/Air mixer to the blower,
then remove the hardware that connects
Содержание MagnaTech BMGH1600
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Страница 98: ...Page 94 BRADFORD WHITE 1 13 12 4 3 5 13 2 15 Final Assembly DETAIL A 9 10 8 Final Assembly ...
Страница 110: ...Page 106 BRADFORD WHITE 6 2 7 11 1 5 4 12 10 3 3 8 9 6 Control Panel Assembly ...
Страница 114: ...Page 110 BRADFORD WHITE 7 8 15 14 9 4 16 12 5 1 6 2 11 AC DISTRIBUTION BOX ASSEMBLY PART NUMBERS MODELS 2500 AND 3500 ...