Sterra Sun — Loud Noise Hissing or Flapping Sound from Motor Fan AreaUpdated 2 days ago
How to Fix Loud Hissing or Flapping Noises on Your Sterra Sun
If your Sterra Sun is making an unusual noise from its fan area, don't panic! These sounds can usually be fixed at home without any tools. Depending on what you hear, the cause is typically very simple:
A Loud Hissing or Whistling Sound: This means air is being choked. It almost always happens if the clear plastic protective packaging around the internal filter wasn't fully removed before installation.
A Flapping, Rattling, or Ticking Sound: This means a small piece of loose debris (like an insect, a piece of string, or paper) has fallen through the top grille and is hitting the spinning fan blades.
Follow these steps to clear the noise and restore quiet operation:
The Mechanical & Filter Inspection Sequence
1.1. Power down and check the casing: Safety First.
Turn the machine OFF and completely unplug it from the wall socket. Let the motor come to a complete stop before moving to the next step.
2.2. Inspect the filter plastic wrap: Eliminates hissing/whistling sounds.
Open the filter compartment door and pull the filter out. Double-check that the clear plastic shipping wrap has been completely unwrapped and discarded. Leaving this plastic on suffocates the motor and creates a loud whistling noise.
3.3. Do a visual check for foreign objects: Eliminates flapping/clicking sounds.
Peer directly down into the top air exhaust grille and look into the empty inner chamber using a flashlight. Check for any trapped debris, loose stickers, large dust bunnies, or insects. If you see something stuck, safely tilt the unit upside down or use tweezers to gently extract it.
4.4. Reinstall the filter tightly and test: Locks the internal housing.
Slide the unwrapped filter back into its slot, ensuring it sits perfectly flush and lock the door securely. Move the unit to an even, flat surface away from tight corners. Plug it back in and turn it on to see if the noise has vanished.
Still hearing the noise after checking?
If you have confirmed the plastic is off, the chamber is empty, and the machine has rested for an hour, but it still makes a loud grinding or flapping noise, the internal fan blade may have become warped or misaligned on its motor spindle.
Log in to our Customer Support Portal.
Submit a support ticket describing the issue.
Attach a short video (at least 1 minute long) showing the error happening. This will help our technical team diagnose and resolve the issue much faster for you.
Thank you for your patience, and we look forward to getting this sorted out!