Heat pumps are a smart and efficient way to heat or cool your home, but when they start giving off a strange smell, it’s hard to ignore. If properly maintained, it shouldn’t be a problem, but if you find yourself wondering, “Why does my heat pump smell?”, you’re not alone – and we’re here to help.
If you notice a musty, fishy, or unpleasant odour from your unit – it’s usually a sign something needs attention. In this blog, we’ll explore the common causes, offer simple solutions, and explain when it’s time to call the professionals.
Common Causes of Heat Pump Odours
Strange smells coming from your heat pump are usually linked to one of the following:
- Mould and mildew: If your heat pump smells musty, chances are mould or bacteria are growing inside the unit. This is often caused by a build-up of moisture and dust in the filters, coils, or drainage system.
- Clogged or dirty filters: Over time, filters trap airborne particles. If they’re not cleaned or replaced regularly, these particles can produce unpleasant smells.
- Dead insects or rodents: A fishy or rotten smell may be due to small animals or insects getting trapped and decomposing inside the unit – especially if the system hasn’t been used for a while.
- Electrical faults: A burning smell might point to overheating components or wiring issues. This needs urgent attention.
- Running in auto mode: Be aware that when the unit switches from cooling to heating in auto mode the coil may accumulate moisture. When the heat cycle starts the heat will evaporate moisture off the coil giving off a musty smell. Cleaning the coils or scheduled maintenance can address this issue.
When to Worry About the Smell
Some odours are more serious than others:
- Persistent musty smell: Often a sign of mould or bacteria, which can affect air quality and trigger allergies.
- Fishy or metallic odours: May indicate electrical problems or overheating parts. Turn off the unit and book a service.
- Rotten or animal smells: Could be a hygiene issue or blockage in the drainage system.
If the smell doesn’t go away after cleaning the filters or airing the room, it’s time to investigate further.
Quick Fixes You Can Try at Home
Before calling in the experts, there are a few steps you can take:
- Clean or replace filters: Most odour issues start here. During heavy usage, check your filters every 15 days. Generally, they should be cleaned – or replaced if needed – every 1-3 months or per manufacturer guidance. Check your manual or our maintenance guide for more information.
- Ventilate the room: Sometimes a stale smell comes from poor airflow. Open windows and let fresh air in.
- Run the unit on ‘fan only’ mode: This can help dry out internal moisture and reduce odour.
If your unit still smells after these steps, don’t ignore it – especially if it’s a recurring issue.
When You Should Book a Professional Clean
If odours persist, it’s time to get your heat pump professionally cleaned. Our Albany-based team specialises in deep cleaning and maintenance for all types of units, including wall-mounted and floor-mounted heat pumps.
A professional service goes beyond just cleaning filters – we check internal coils, drainage trays, and ensure no mould, bacteria, or foreign objects are hiding in the system. We also inspect electrical components for signs of damage.
Get onto it ASAP
Strange smells from your heat pump shouldn’t be ignored. Whether it’s mould, a blocked filter, or something more serious, identifying the cause early can save you from bigger issues down the line. While basic maintenance helps, a deep clean is often the most effective solution.
Odour issues? Time for a deep clean. Enquire now.