Air Proving Switch - Wayne LC2300M Manual

8. Pull the burner body straight back along the slides until you get a gap of approximately
8 inches. The burner head assembly can now be removed, see Figure 19.
Figure 19
When servicing, clean burner head ports, electrodes and sensor probe. Inspect the sensor probe and
electrode wires and ceramic insulators carefully for hairline cracks, which might provide an electrical
leak path that could short out the ignition spark, or flame signal.
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 (SECTION V - Figure 21).
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 ceramic.
D. AIR PROVING SWITCH
The Air Proving Switch is mounted on the right side of the burner housing. Tubes connect the air
proving switch to fittings on the side of the blower housing assembly. The tubing allows pressurized
air from the blower housing to travel to the air proving switch causing the diaphragm to close a set of
micro-switch contacts, thus completing the circuit. The function of the Air Proving Switch is to ensure
that the blower motor and blower wheel are developing sufficient combustion air. Should the blower
motor fail or the blower wheel malfunction, the voltage to the gas valves is interrupted.
The air proving switch should never require maintenance. However, should nuisance lockouts occur,
the switch can be checked. Disconnecting the 24V leads from the air proving switch and "jump" the
leads together will bypass the switch's function. If the burner functions correctly, the switch is
malfunctioning and should be replaced.
As mentioned above, the switch should never require maintenance. However, a pinched or blocked
tube will shut off the flow of pressurized air to the diaphragm creating a failure like a bad air proving
switch. Always check to ensure that the clear tubing is not pinched.
63899-002 Rev. A 3/20/2024
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