What might create a spanking new gas Furnace to confer past its sell-by date a non-stop, high-pitch, humming/buzzing nouns? It's a Lennox. The sound can be described as a...

It's a Lennox. The sound can be described as a non-stop ringing swish like a giant pitched whining, buzzing, hissing, humming sound much resembling Tinnitus.
Basement flooded. Sump out. Pilot on dampen heater/heater?
Answers:    Gas Furnace Has Noisy Operation
Possible Causes

Higher pitched "squealing" sound may be cause by slipping blower belt or motor or shaft bearings surrounded by need of oil
Lower pitched "rumble" sound may be cause by a poorly adjusted pilot fluffy if this problem occurs beside the burners off.
Lower pitched "rumble" nouns may be caused by dirty gas burners if the problem occur with the burners on.
Possible Repairs

Oil blower motor lubrication ports (usually at respectively end of shaft) beside light solidity oil
Check for proper belt stiffness. Belt should depress about 1" at center of span.
If too loose, tighten belt.
Replace frayed belt.
Adjust pilot standard lamp
Call furnace service technician to have burners in synch or cleaned.
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might be something in the supporter, if its still under warranty nickname them,