How to clean an air conditioner – the expert method for a cool, efficient unit

Wondering how to clean an air conditioner? These tips will ensure your home is ready for the hotter months ahead

How to clean an air conditioner
(Image credit: GettyImages)

Most homes across the US have some form of AC, so knowing how to clean an air conditioner is a skill that many of us need to have – especially at this point of the year. 

As we approach the summer months, your thoughts may be turning towards switching on the air conditioner again – but cleaning your AC unit is a sensible step to take beforehand. 

As with many cleaning tips, those for cleaning an air conditioner at home are quick and simple to follow, but you do need to tread with caution. Here's how to clean an air conditioner quickly, efficiently – and safely. 

How to clean an air conditioner – 6 steps to success  

Air con

(Image credit: GettyImages)

'Regular AC maintenance and cleaning is good for its cooling and extends the life span of the unit,' says Alicia Johnson, the Founder of Cleaning Green LLC in California. 

If you follow these expert-approved steps regularly, it could save you a lot of money in the long run – and ensure your unit runs smoothly throughout the season. Here's what you need to know. 

1. Turn the power off 

Before cleaning anything electronic, you should ensure you have removed its power supply – and an air conditioner is no exception. 

Alicia warns that you should never attempt to clean a running air conditioner as this will put you in significant danger. Before beginning, you should locate the source of your AC's power supply and turn it off completely. 

2. Replace or clean the filters 

The easiest but most impactful step is the cleaning of your air conditioner filters. However, the expert recommends removing and buying new filters (such as these on Amazon) if you notice any signs of damage. 

'You can find them in the air handler or furnace cabinets inside or at the end of the air inlet,' Alicia says. 'To ensure good airflow, the filters must be thoroughly sanitized or replaced twice annually because of the dirt, hair, and dust that can clog them.' 

3. Clean the condenser coils 

Next, you need to tackle the Condenser Coils. Alicia recommends using a screwdriver to remove the top and side panels (to protect the condenser system from access) and reach the unit's condenser coils. 

'After unscrewing the panel, lift the top gently since being aggressive could cause damage to the wirings,' the expert warns. She suggests using a soft brush or a special coil brush for the best results but warns that this step comes with extra caution.

'The coils are extremely delicate, and even the slightest pressure can bend and damage them,' Alicia says. After the outside of the coil is done, you should use your vacuum cleaner for the inside. 

'If you notice any persistent dust or debris that refuses to budge, you can use a commercial AC coil cleaner and spray it on the inside. Just don't spray against the fan or any other electrical components,' she suggests.

Air con

(Image credit: GettyImages)

4. Clear the condenser 

Your condenser is vital to the cooling process of your air conditioner – so it is important that you clear any leaves, debris, or garden weeds that have found their way inside. 

'If you spot a drain at the bottom, make sure nothing blocks the draining hole,' Alicia explains. 

If you’re looking for how to get rid of weeds and other garden matter, she recommends cleaning the blower's fan blades using a rag and vacuum. She adds that it's good practice to spray WD-40 in case the fan motor contains oil ports.

You should then dry out any excess water present inside the unit once the cleaning is done before reconstructing the condenser. 

'Make sure there aren't any twigs, vines, leaves, or weeds present inside that can hinder the flow of your unit,' Alicia adds. 

5. Inspect the refrigerant lines 

If the foam insulation covering your refrigerant line sustains damage, now is the time to change it. Alicia suggests replacing the entire piece to maintain the level of efficiency your cooling system provides. 'However, if the damage is minor, you can just wrap the spot using insulation tape,' she adds. 

6. Test your results 

Before restoring the power supply and activating the power to the condenser, Alicia says that you should switch the thermostat to the off setting. 

'Adjust the cooling mode you normally keep the AC at using the thermostat and activate the cooling system. You will notice a much better cooling experience if you have done everything right,' she says. 

Air con

(Image credit: GettyImages)

What's the best thing to use to clean an air conditioner? 

Alicia Johnson, the Founder of Cleaning Green LLC, recommends investing in an all-in-one air conditioner universal cleaning kit (these are sold at Amazon) which will allow you to clean your unit by yourself thoroughly. This should contain most of the essentials needed to clear out your AC (aside from a vacuum and the WD-40, naturally).

Is it safe to spray water on a running air conditioner? 

No, it is not safe. While some may question whether it is safe to spray water on a running air conditioner, Alicia Johnson, the Founder of Cleaning Green LLC strongly warns against this cleaning method. 

'Spraying water on the AC while it's running could lead to electrocution since the current is running throughout the unit; she says. 'Any contact between the electricity and water could put your life at risk.'

This is one cleaning method that should be avoided at all costs. 

Megan Slack
Megan Slack

Megan is a News Writer across Future Plc’s homes titles, including Homes & Gardens and Livingetc. As a News Writer, she often focuses on emerging microtrends, sleep and wellbeing stories, and celebrity-focused pieces. Before joining Future, Megan worked as a News Explainer at The Telegraph, following her MA in International Journalism at the University of Leeds. During her BA in English Literature and Creative Writing, she gained writing experience in the US while studying in New York. Megan also focused on travel writing during her time living in Paris, where she produced content for a French travel site. She currently lives in London with her antique typewriter and an expansive collection of houseplants.