Lesson page
Musty smell and startup odour
Use this page to explain the smell, check the filters, and decide if the unit needs a deeper clean.
What this usually means
A musty smell when the unit starts is a practical warning sign. It often points to moisture, dust, or buildup deeper inside the air con, not just a dirty front filter.
Do this first
Turn the unit off. Open the cover. Check and clean the filters before running it again.
4-step check before you book
1
Open the front cover
Expose the filters and look at what is sitting behind them.
2
Slide the filters out
Pull them toward you carefully so you do not drop dust back into the room.
3
Wash them properly
Use a safe biodegradable solution if needed and rinse from the back first.
4
Let them dry fully
Put the filters back only when they are dry. If the smell returns, the issue is likely deeper inside.