Hear the cycle
Sound Lab
Listen for the trigger, not only the noise.
Rhythm, system cycle and strongest location often distinguish movement, flow, vibration and electrical signals.
Describe your clue →Combustion or motor operation01
Furnace rumbling
Low-frequency rumble tied to appliance operation requires system-specific inspection.
- Trigger
- burner or fan start
- Strongest location
- heating appliance
Sensory method
Describe first. Interpret second.
- TriggerWhat changed immediately before it began?
- CycleDoes it follow startup, flow, heating, wind or room use?
- LocationWhere is it strongest, and does that move?
- Stop conditionHeat, smoke, gas or electrical odor changes the response immediately.
