Help!! My AC Unit is Hissing and Bubbling! It’s a dreaded moment for any Floridian: The relentless summer sun is beating down on your house, the humidity and temperature outside are skyrocketing and you hear a bubbling or hissing sound coming from the air conditioning unit inside your home. With a sinking feeling, you realize that your central air conditioning has not been keeping your home as cool as it did in the past. Now what? Click on our link to find out.