Laars MagnaTherm MGH1600 Installation And Operation Instructions For

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Laars MagnaTherm MGH1600 Installation And Operation Instructions For Manual pdf 87 page image

MagnaTherm Boilers and Water HeatersPage 83After the valve has been removed, reassemble inreverse order making sure to include all gasketsand O-rings. Turn on the manual gas valves andcheck for gas leaks. Turn on the main power. Placethe unit in operation following the instructions inSection 10. Once the boiler is operating, check forleaks again and confirm all fasteners are tight.Check the setup for the unit according to theinstructions in Section 9.11.B.3 ControllerEach unit has an integrated controller thatincorporates manual reset high limit control,operating temperature control, modulating control,ignition control, outdoor reset control, pump controland many other features. If any of these featuresare thought to be defective, please consult thefactory for proper troubleshooting practices beforereplacing a control.If it is necessary to replace a controller, turn offall power to the unit and shut off all manual gasvalves to the unit. Open the front doors to theunit. Remove all wire connections from the controlboard. The control board connections are keyedto only allow connection in the proper location, butproper handling techniques should be used to avoiddamage to the wiring or connectors. To remove thecontrol, undo the mounting screws. To replace thecontrol repeat the steps listed above in the reverseorder making sure to connect all wires in the properlocations. Place the unit in operation following thesteps outlined in Section 10.11.B.4 Spark Ignition ElectrodesThe spark ignition electrode is a dual rod assembly.The ground rod is fastened to the mounting bracketof spark electrode assembly. The spark electrodepasses through a ceramic insulator and then alignswith the ground rod. In order for a proper spark toform, the mounting bracket must be grounded tothe boiler chassis. To remove the spark ignitionelectrodes shut off the power to the unit, turn offthe main gas supply and open the front door of theboiler to gain access to the top portion of the unit.Remove the high tension ignition wire from thespark electrode. Remove the two nuts and spacerholding the spark electrode assembly in place. Pullthe spark ignition electrodes out of the boiler slowlymaking sure to move the assembly as need, so theelectrodes are not bent as they are being removed.If the old assembly is determined to be defective,install a new spark assembly in the reverse order,replacing the gasket if necessary.11.B.5 Flame SensorThe flame sensor is a single rod system. The minimumflame signal that will allow the unit to fire is 0.8 volts. Toreplace the flame sensor electrode, shut off the powersupply to the boiler. Turn off all manual gas valvesconnecting the boiler to the main gas supply line. Openthe front doors of the boiler to gain access to the flamesensor electrode. Remove the flame sensor wire fromthe electrode. Remove the two nuts fastening theelectrode to the burner plate. Remove and replacethe old flame sensor gasket. If the old electrode isdetermined to be defective, reinstall a new flamesensor electrode in the reverse order.CAUTIONThe igniters and sensors can become very hot.If you touch these parts accidentally, this cancause burns or injury.11.B.6 Blower 1600The combustion air blower is a high pressure centrifugalblower with a variable speed motor. The blower is drivenby the control system using a PWM signal.If it is necessary to service, remove or replace theblower, the Main Power MUST be disconnected andthe main gas supply to the unit must be turned off.Open the doors and remove the doors from theirhinges. Remove the top and top side jacket panels.Remove the fasteners holding the fuel/air mixer to theblower inlet. Remove the hardware that is connectingthe blower outlet to the unit’s adapter plate. If theblower is determined to be defective, replace theexisting blower with a new one and assemble in thereverse order. Be sure to install all of the requiredgaskets and O-rings between the blower adapter plateand air/fuel mixer.11.B.7 Blower 2000-4000The combustion air blower is a high pressurecentrifugal blower with a variable speed motor drivenby a factory installed VFD located in the high voltagebox. The speed of the motor is determined by thecontrols logic which is delivered to the VFD by a0-10VDC signal.If it is necessary to service, remove or replace theblower, the Main Power MUST be disconnected andthe main gas supply to the unit must be turned off. Toreplace or remove the blower, turn off main power,remove hardware that connects the Fuel/Air mixer tothe blower, then remove the hardware that connectsthe blower to the adapter plate. If the fan isdetermined to be defective, replace the existing fanwith a new one by reversing the steps listed above.Be sure to install all the required gaskets and o-ringsbetween blower, adapter plate, and Fuel/Air mixer.