Laars Mascot II, Installation And Operation Instructions Manual

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LAARS Heating Systems
Page 36
ignitor assembly in the reverse order if the old assembly
is determined defective. Replace gasket if necessary.
11.2.4 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. Reinstall a new flame sensor
electrode in the reverse order if the old electrode is
determined defective.
Caution
Igniters and sensors get hot and
can cause burns or injury.
11.2.5 Blower
The combustion air blower is a high-pressure
centrifugal blower with a variable speed motor. Speed
of the motor is determined by the control logic. 120
Volts remain on to the blower at all times. If a blower
change is required, 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 above. Make sure to install all of the
required O-rings and gaskets between the blower arm
and the blower and blower face and venturi flange.
11.2.6 Heat Exchanger Coils
Black carbon soot buildup on the external surfaces
of the heat exchanger is caused by one or more of the
following; incomplete combustion, combustion air
problems, venting problems and 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 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
per the following:
Caution
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. Remove the four bolts connecting the blower
flange to the burner door arm.
4. Remove the nuts located on the outside diameter
of the burner door to the heat exchanger.
5. Remove the burner door/burner assembly from the
heat exchanger.
6. Disconnect the condensate drain line.
7. Attach a longer hose to drain and run to a bucket.
8. Clean the heat exchanger by brushing light
accumulations of soot and debris. Use a brush with
soft bristle (non metal) to avoid damaging the
surface of the heat exchanger tubes.
9. 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, which is being diverted into a
separate container.
NOTE: The Warranty does not cover damage caused
by lack of required maintenance, lack of water flow,
or improper operating practices.
WARNING
Failure to rinse the debris from the heat exchanger
and temporary drain line may lead to clogged
condensate lines, traps and neutralizers. Condensate
pumps (if used) may also be damaged from the
debris left behind, possibly causing property damage.
11. Install all components removed in the reverse
order to place the appliance back in operation.
Make sure all gaskets are in place as components
are installed. Replace any damaged gaskets. Do
NOT reuse damaged gaskets.
12. Place the appliance in operation according to
Section 10 checking all gas connections for leaks.
Confirm all fasteners are tight.
11.2.7 Gas Conversion
Mascot II units can be converted from natural to
propane gas or from propane to natural gas easily in the
field. If a gas conversion is performed, the unit must be
identified with the appropriate gas labels and a
conversion sticker to allow technicians performing
maintenance in the future to properly identify the gas
type of the appliance. These stickers are included with
the boiler during shipment.
WARNING
This conversion shall be installed by a qualified
service agency in accordance with the
manufacturer's instructions and all applicable codes
and requirements of the authority having jurisdiction.
If the information in these instructions is not followed
exactly, a fire, an explosion or production of carbon
monoxide may result causing property damage,
personal injury or loss of life. The qualified service
agency is responsible for the proper and complete