The answer to 'carpet cleaning smells bad' is that there are several common causes, including mold or mildew growth, leftover cleaning solution, or pet odors that weren't properly removed. Symptoms may include a musty, sour, or ammonia-like smell that lingers after cleaning. To address this, you'll want to first determine the root cause and then take the appropriate steps to resolve it.
If the smell is due to mold or mildew, you'll need to thoroughly clean and disinfect the carpet, and address any underlying moisture issues. If it's leftover cleaning solution, you may need to do additional rinsing. And for pet odors, enzymatic cleaners can help break down the odor-causing compounds. In some cases, it may be best to call in a professional carpet cleaning service, especially if the odor is severe or you're unable to identify the source.