MG3P Installation Manual

35
7. Remove the piping between the Gas Valve and the ground-
joint union. (If applicable).
8. Remove all screws securing the Manifold Assembly to the
Burner Box.
9. Carefully remove the burner assembly from the furnace. DO
NOT DAMAGE THE IGNITER WHILE REMOVING THE
BURNER ASSEMBLY.
10. Inspect the burners for accumulated dust or debris. If
necessary carefully clean them with a soft wire brush and a
vacuum cleaner. DO NOT DAMAGE THE IGNITER WHILE
CLEANING THE BURNER.
11. Replace all the parts in reverse order from which they were
removed.
12. Follow the lighting instructions found on the furnace door to
return the furnace to operation. Verify proper operation after
servicing.
Heat Exchanger & Burner Maintenance - The furnace
should operate for many years without soot buildup in the flue
passageways, however, the flue, vent system, and burners should
be inspected and cleaned (if required) by a qualified service
technician annually to ensure continued safe operation. Pay
attention to any deterioration from corrosion or other sources.
Lubrication - The bearings in the blower motor and inducer
blower used in these furnaces are pre-lubricated and sealed by
the manufacturer. No further oiling of the bearings is required
for the life of the motor.
Vent System - Check the inlet pipe (if applicable) and outlet
pipe to ensure they are not blocked by any debris. Damaged
vent pipe sections must be replaced and any obstructions or
blockages must be removed before operating the furnace.
WARNING:
Holes in the vent pipe or heat exchanger can
cause combustion products to enter the home.
Replace the vent pipe or heat exchanger if leaks
are found. Failure to prevent the circulation of
combustion products into the living space can
create potentially hazardous conditions including
carbon monoxide poisoning that could result in
personal injury or death.
Air Filter(s) - An air filter is supplied with the furnace as shipped
from the factory. It is recommended that filters be cleaned or
replaced monthly during the heating season.
WARNING:
Never operate the furnace without a filter in place.
Dust and lint can build up on internal components,
resulting in loss of efficiency, equipment damage,
and possible fire.
New or newly renovated homes may require more frequent
changing until the construction dust has minimized. Filters
designed to remove smaller particles such as pollen, may require
additional maintenance. Filters for side return and bottom return
applications are available from most local distributors.
Upflow Furnaces: the filter is located inside the blower
compartment underneath the blower. To replace the filter:
1. Remove the lower compartment door.
2. Slide the filter backwards until the edge of the filter clears the
front flange of the furnace.
3. Lift the filter up over the flange and out through the front of
the furnace.
4. Install new filter in reverse order of the removal instructions.
NOTE: Center the filter over the return opening and secure
it to the fastener at the rear of the furnace compartment.
Downflow Furnaces: the filter sits on three filter brackets located
on top of the furnace. The filter can be easily removed and
replaced. Do not remove the filter brackets. When installing the
new filter, make sure it is centered over the return air opening.
Blower Compartment - Dirt and lint can create excessive
loads on the motor resulting in higher than normal operating
temperatures and shortened service life. It is recommended
th-at the blower compartment be cleaned of dirt or lint that may
have accumulated in the compartment or on the blower and
motor as part of the annual inspection.
Cleaning of Burners - If the burners must be cleaned, follow
steps 1 - 12. See Figure 55 (page 54) for component location
and identification.
1. Shut off gas supply to the furnace at the meter or at a manual
valve in the supply piping.
2. Turn off all power to the furnace and set the thermostat to it’s
lowest setting.
3. Remove the burner door from the furnace.
4. Turn the gas control switch to the OFF position.
5. Disconnect the wires from the gas valve, igniter, flame sensor,
and flame rollout switch.
6. Using two wrenches, separate the ground-joint union in the
gas supply piping at the furnace.