How to clean a split system air conditioner

Keeping your air conditioner in tip-top shape is the best way to get healthy airflow and a more energy-efficient system. Besides that, knowing how to clean a split system air conditioner can help extend the life of your unit and save on running costs. Here’s everything you need to know.

In this article, we cover everything you need to know about cleaning your split system air conditioning unit, with topics including: 

• Why cleaning your split system air conditioner matters

• How to clean a split system air conditioner

• Pain points in DIY split type aircon cleaning

• How regularly should I clean my split system air conditioner?

• Is it worth hiring a professional air conditioning service?

• When is the best time to clean a split system?

Why cleaning your split system air conditioner matters

Over time, dust, pollen and even mould can build up inside your split system air conditioner. A dirty aircon doesn't just perform poorly - it can spread allergens, consume more energy, and shorten your unit's lifespan.

Regularly cleaning your split type aircon improves:

• Air quality by reducing dust, mould and bacteria

• Running power by letting the system cool your home without overworking itself

• Longevity by preventing mechanical issues caused by dirt build-up

How to clean a split system air conditioner

Basic cleaning of your split system air conditioner isn't too difficult as a DIY job if you follow the right steps. Here's how:

• Turn off the power: Safety first! Always turn off the air conditioner at the wall before starting any cleaning

• Remove and clean the filters: To clean your filters, open the front panel of the indoor unit and gently remove the air filters. Once you’ve done that, vacuum the filters to remove any dust and wash them with warm soapy water if needed. Always let your filters air-dry completely before putting them back in your split system air conditioner

• Wipe down the louvres: The louvres are the blades on your aircon that direct airflow, and they can collect dust too. Wipe them down gently with a microfibre cloth or use the soft-brush attachment on your vacuum

• Clean the evaporator coil: If you can access the evaporator coil, lightly dust it with a soft brush. Don’t use too much force or liquid – it's best to leave deep-coil cleaning to the professionals to avoid any damage to the delicate components

• Clean the outdoor unit: Like your indoor unit, your outdoor air conditioning unit needs some love and care too. Clear any leaves and dirt from around the outdoor condenser unit and gently wipe or vacuum the fins (the thin metal slats) to help airflow. Avoid using high-pressure water sprays on the outdoor unit, as this could bend the fins or damage internal parts

Pain points in DIY split type aircon cleaning

While basic cleaning tasks like dusting filters are manageable, a full internal clean can be challenging or even dangerous. Problems you might come across if you clean your air conditioner yourself include:

• Hidden mould growth that you can't see without disassembling the unit completely

• Blocked drain pipes that can cause water to leak inside your home

• Difficult-to-reach components like the evaporator coil and fan motor

• Accidental damage to sensitive parts, which will void your warranty

For a thorough, deep clean – including chemical cleaning to remove mould and sanitise your system – it's best to hire an experienced air conditioning technician.

How regularly should I clean my split system air conditioner?

The frequency that your split system air conditioning unit needs to be cleaned varies depending on its different parts. As a general guide: 

• Air filters should be cleaned every 6–8 weeks during peak-use periods

• Louvres and casings can be wiped down every few months

• Professional deep cleaning is recommended at least once a year, especially before summer.

If you have pets, live in a dusty area or suffer from allergies, you might need to clean your system more often.

Is it worth hiring a professional air conditioning service?

Absolutely. While DIY maintenance is fine for surface-level cleaning, a professional air conditioning service will:

• Remove built-up mould, dirt and bacteria

• Flush condensate drains to prevent leaks

• Do pressure checks and inspect for refrigerant leaks

• Disassemble components and clean them thoroughly

Hiring a professional means your air conditioner will stay as hygienic and efficient as possible – without risking voiding your warranty. Plus, you'll enjoy better air quality and lower energy bills.

When is the best time to clean a split system?

The ideal times to clean your split system air conditioner are:

• Spring, before the heat of summer

• Autumn, after lots of use throughout summer

Regular maintenance before peak seasons means your system will always run as efficiently as possible when you need it most. It’ll also help avoid any potential breakdowns on scorching-hot days.