The answer to 'why is my heat pump smells bad' is that there are several common causes, including refrigerant leaks, mold or mildew buildup, and issues with the compressor or other components. The smell could indicate a more serious problem that requires professional attention.
If you notice a musty, rotten, or burning smell coming from your heat pump, it's important to address the issue promptly. Refrigerant leaks can be dangerous and lead to further damage, while mold and mildew can compromise indoor air quality. In some cases, the smell may be caused by an issue with the compressor or other mechanical parts, which could require repair or replacement.