Wayne HSG200 Manual - page 16
PAGE 15
SECTION IV
SERVICE
Caution: Make sure the main manual, combination
valves and main power switch are turned
off before opening burner or removing any
parts for service.
A. BURNER HEAD AND
ELECTRODE/SENSOR ASSEMBLY
The burner head, electrode, sensor probe,
combination valve, orifice housing and housing
cover are part of the gas train assembly which can
be removed as one unit. (See Figure 15)
1. Disconnect gas line from combustion gas valve
inlet, flame sensor lead wire from gas primary,
gas valve lead wires from gas valve operator
and (orange) ignition lead wire from ignition
transformer ignition lead wire.
2. Remove the two 1/4” (6.35mm) hex slotted
screws on the top front of the housing cover and
the two 5/16” (7.9375mm) hex slotted screws
on the left and right side back of the housing
cover.
3. To remove gas train assembly, gently lift up rear
of housing cover pulling rearward slightly on the
drawer assembly gradually positioning the rear
of the drawer assembly upward 90 degrees
(1.57RAD). Gently extract burner head and
electrode/sensor assembly out opening in
housing taking extreme care to not dislocate or
damage electrode or sensor probe.
4. When servicing, clean burner head ports,
electrodes and sensor probe. Inspect the
sensor probe and electrode wires and porcelain
insulators carefully for hairline cracks which
might provide an electrical leak path that could
short out the ignition spark, or flame signal.
5. Examine the electrode and sensor probe for
any serious corrosion or deterioration of metal
at the tips. Check for proper dimensional
settings of the sensor probe and electrode (see
Figure 13). Adjust and/or replace these
assemblies as necessary. Make sure that the
ignition and sensor probe wires go to the
correct electrodes and the ignition wire boot is
in place over the electrode porcelain.
6. Make sure that the burner tube end is properly
positioned in the combustion chamber entry. It
must be set 1/2” (12.7mm) short of the inside
face of the combustion chamber as shown in
figures 4, 5 or 6.
B. AIR PROVING SWITCH
The air proving switch is mounted to the housing
cover with (2) #6 self tapping screws under the gas
valve. A clear plastic tube, protected by a spring
cover, is connected to the barbed fitting on the
pressure switch while the other end is connected to
a brass barbed fitting. The plastice tube allows
pressurized air from the blower housing to travel to
the pressure switch causing the diaphragm contacts
to close thus completing the circuit.
The function of the air proving switch is to ensure
sufficient combustion air is being developed by the
blower motor and blower wheel. Should the blower
motor fail or the blower wheel malfunction, the
burner gas valve will shut off.
1. The air proving switch should never require
maintenance. However, should nuisance
lockouts occur, the pressure switch can be
checked. This is done by disconnecting the
yellow and white leads from the Air Proving
switch and jumpering the leads together. If the
burner functions correctly, the switch needs to
be replaced.
WARNING: If a jumper is used to check the switch it
must be removed or an unsafe condition
can occur resulting in death or property
damage.
2. As mentioned above, the switch should never
require maintenance. However a pinched tube
will shut off the flow of pressurized air to the
diaphragm creating a failure made similar to
bad Air Proving switch. Always check to ensure
that the clear tubing is not pinched. Make sure
the spring cover is reinstalled over tube.
3. Switch is mounted in the horizontal position with
terminals up from factory. Final burner mounting
should maintain horizontal switch position.
WARNING: Damage to internal components of
burner may result, if burner is mounted in other
than horizontal position.
C.
COMBUSTION AIR BLOWER AND MOTOR
1. Cleaning of the combustion air blower is
indicated if the blades show an accumulation of
dust and lint, or if the character of the flame
indicates a deficiency of combustion air.
2. The side plate, motor and blower wheel are
removed as one assembly. Disconnect the
motor wire inside the junction box beneath the
ignition transformer. Remove the four (4) 5/16”
(7.9375mm) hex slotted screws securing
sideplate to fan housing.
CAUTION: Do not remove blower wheel from motor
shaft during periodic cleaning.
3. Should removal of the blower wheel be
necessary for cleaning or replacement of it or
the motor, the blower wheel must be positioned
correctly on the motor shaft. (Figure 16)
HSG200 blower wheel p/n 21664 is positioned
2 1/16” (52.3875mm) measured from the blower
wheel inlet ring face to the side plate face.
HSG400 blower wheel p/n 21642 is positioned
2 3/16” (55.5625mm) measured from the blower
wheel inlet ring face to the side plate face.