Why Is My Aircon Leaking? Causes, Consequences, and How to Fix It

You're lying on your sofa when you hear dripping sounds from your aircon unit. That sound means water is leaking somewhere it shouldn't be.

This can stress you out fast, especially when you spot puddles on the floor or water stains creeping up your walls.

The air conditioner is most likely leaking because of a clogged drain line, dirty filters, or a full drain pan that can't handle the excess water.

In Singapore's humid climate, your aircon works extra hard to remove moisture in the air. When something blocks this process, water backs up and leaks out.

Quick action matters because water damage can ruin your floors, walls, and furniture. It can also create mold problems that affect your health.

The good news? Many cases of air conditioner leaking have simple fixes you can try yourself, while others really need a professional. Let's examine the most common causes, what to do immediately, and when to seek assistance.

Key Takeaways

• Most aircon leaks come from blocked drain lines, dirty filters, or overflowing drain pans that stop water from draining properly.

• Turn off your aircon immediately and clean up water to prevent damage while you decide between DIY fixes or calling a pro.

• Regular cleaning and yearly maintenance can prevent most aircon leaks in Singapore's humid climate.

Why Is My Aircon Leaking?

Your aircon leaks when something blocks or breaks the normal water flow system. Most leaks start because water can't drain properly from your unit.

The most common causes include:

• Clogged drain line – Dirt and dust block water from flowing out.

• Dirty air filters – Blocked filters cause ice to form and melt.

• Full or broken drain pan – Water overflows when the pan can't hold more.

• Low refrigerant – Makes coils freeze and create excess water.

• Broken condensate pump – Can't remove water from the drain pan.

• Poor installation – Uneven units cause water to leak instead of drain.

A dirty air filter is a big culprit. When filters get clogged, air can't reach the evaporator coil properly.

This makes the coil freeze and build up ice. When the ice melts, it makes more water than your drain pan can handle, so the water spills out.

A clogged drain line is another top reason. Fungus, dirt, and dust build up in the drain pipe over time, stopping water from flowing out normally.

Quick signs to check:

• Water pools under your unit

• Water stains on walls or ceiling

• Bubbling sounds (could mean refrigerant leak)

• Warm air is coming out instead of cool air

Small leaks near the drain pipe on hot days are normal. But big leaks or leaks from other parts? Those need professional repair right away.

Immediate Actions for a Leaking Aircon

Quick action can save your home from water damage and protect you from electrical hazards. The first steps are to shut down your system, protect your belongings, and seek professional help.

Turn Off Your Air Conditioner

Switch off your aircon immediately when you notice water leaking. This stops further damage and keeps you safe from electrical dangers.

Turn off the power at the main switch, not just the remote control. Water and electricity together? Not a good mix.

Why turning off matters:

• Prevents electrical shock hazards

• Stops more water from leaking

• Protects your aircon from getting worse

• Reduces risk of short circuits

Don't try to move the unit while it's still plugged in. Water conducts electricity and can cause injuries.

If water has reached electrical outlets near your air conditioner, don't touch them. Call an electrician if you're not sure about safety.

Clean Up Spilled Water

Remove water quickly to prevent damage to your floors, walls, and furniture. Fast cleanup also stops mold and mildew from growing.

For different surfaces:

• Wood floors: Wipe up puddles right away to stop water from seeping into the wood.

• Walls: Clean water off painted surfaces to keep paint from bubbling or peeling.

• Carpets: Use towels to soak up as much water as you can.

Place towels or buckets under the leak to catch drips. Change them regularly so they don't overflow.

Use a dehumidifier in the room to lower moisture levels. This helps prevent mold while you wait for repairs.

If the weather's good, open windows for ventilation. Good airflow dries the area faster.

Contact a Qualified Professional

Professional aircon repair companies have trained technicians who can actually figure out what's wrong and fix aircon leaks safely. They've got the tools and experience for complicated repairs.

Don't try major repairs yourself. Clogged drains, damaged parts, or refrigerant leaks really need someone who knows what they're doing.

When calling for help:

• Describe where the leak is and how big it is

• Mention any weird sounds or smells

• Say how long the leak's been happening

• Ask if they offer emergency service

Book an appointment as soon as you can. Waiting just makes things worse and usually costs more in the end.

If you smell chemicals or hear bubbling, tell the technician. These could be signs of a refrigerant leak, which needs urgent attention.

Is a Leaking Aircon Dangerous?

A leaking air conditioning unit isn't just a hassle—it can seriously mess up your home and your health.

Water damage destroys walls and furniture. Electrical parts mixed with water? That's a fire hazard waiting to happen.

Potential Home Damage

Water from your leaking aircon can cause expensive problems. The water spreads fast, soaking into wooden floors and making them warp or rot.

Your walls and ceilings take a hit too. Water stains show up first, but the real trouble happens behind the scenes as drywall softens and crumbles.

Common damage includes:

• Warped hardwood floors

• Stained carpets and rugs

• Ruined furniture and electronics

• Peeling paint and wallpaper

• Damaged wood structures

The longer you wait, the pricier repairs get. What starts as a small puddle can turn into thousands in repairs.

Electrical Hazards

Water and electricity together are just dangerous. Your aircon's electrical parts can short circuit if water touches them.

This can cause fires or electric shocks. Water can also travel along wires and reach outlets or switches near your unit.

You should turn off the aircon immediately if you see any leaking. Never try to repair electrical stuff yourself when water's around.

Safety steps to take:

• Switch off power at the breaker

• Unplug the unit if it's safe

• Keep kids and pets away

• Call a qualified technician

Mold and Health Risks

Leaked water creates perfect conditions for mold. Mold spores start growing within 24-48 hours in damp spots near your aircon.

Mold and mildew bring nasty smells and real health issues. You might notice coughing, sneezing, or trouble breathing.

People with asthma or allergies have a tougher time. Mold exposure can trigger bad reactions and make breathing problems worse.

Health symptoms from mold:

• Persistent coughing

• Runny or stuffy nose

• Eye irritation

• Skin rashes

• Headaches

The humid air also attracts insects and pests. These unwanted guests can spread even more health risks in your home.

10 Common Reasons Why Your Aircon Is Leaking Water

Air conditioning units leak water for all sorts of reasons—mechanical issues, skipped maintenance, you name it. Most leaks happen when water can't drain properly or ice forms and melts inside the unit.

1. Clogged Drain Pipe

Your aircon's drain pipe carries water away from the unit. When dirt, dust, and debris clog the drain line, water can't flow out like it's supposed to.

The blockage forces water to back up. That backup water then overflows and leaks from your aircon.

Common signs of a clogged drain pipe:

• Water pooling around your indoor unit

• Musty smells from your aircon

• Gurgling sounds while it runs

You can try clearing minor clogs with the wet vacuum. Point it at the drain line opening and suck out the blockage. For stubborn clogs, you'll need a pro.

2. Dirty or Blocked Air Filters

Dirty air filters cut airflow to your evaporator coil. When air can't move, the coil gets too cold and freezes.

Ice forms on the coil, and the ice melts, it creates way more water than your drain pan can handle.

The air filter maintenance schedule:

• Clean washable filters every 2 weeks

• Replace disposable filters monthly

• Check filters more often if you use your aircon a lot

Blocked filters also allow dust to enter your system. That dust can clog your drain line and make the leak worse.

3. Frozen Evaporator Coil

Your evaporator coil freezes if it gets too cold, usually from poor airflow or low refrigerant.

Ice buildup stops your air conditioner from cooling properly. When the ice melts, it releases a large amount of water, overflowing your drain pan.

What causes coil freezing:

• Dirty air filters choking airflow

• Low refrigerant

• Blocked air vents in your room

• Running your aircon when it's already pretty cold out

If you see ice on the coil, turn off your aircon. Let it thaw out before starting it up again. You'll need to address the root problem, or it'll freeze again.

4. Low Refrigerant Levels

Refrigerant is the liquid that cools the air in your aircon. When the level gets too low, your evaporator coil can freeze up.

Low refrigerant usually means there's a leak somewhere in your system. The refrigerant shouldn't just disappear during normal use.

Signs of low refrigerant:

• Ice forming on the evaporator coil

• Warm air coming out of the vents

• Hissing or bubbling noises

• Noticeably higher electricity bills

Don't try to top up the refrigerant yourself. It can irritate your skin and lungs. Leave refrigerant repairs to trained technicians.

5. Broken Condensate Pump

The condensate pump removes water from your drain pan. If it fails, water builds up and spills over.

Dirt or debris can clog the pump, and electrical faults can prevent it from functioning altogether.

Pump problems to watch for:

• Water not draining from the pan

• Strange noises coming from the pump

• The pump runs, but the water doesn't move

Most pump problems need a professional. Sometimes, the pump simply needs a thorough cleaning, but at other times, it may require replacement.

6. Improper Installation (Tilted Unit)

Your air conditioner has to sit level for water to drain properly. If it's tilted or uneven, water will flow away from the drain, causing leaks.

Leveling problems typically occur most frequently with new AC installations. Over time, poor mounting or settling can also cause things to become unbalanced.

Check your unit's position:

• Look for obvious tilting or sagging

• See if water gathers in odd spots

• Notice if leaks started after installation

A simple level tool will show if your unit sits straight. Sometimes, you'll need a pro to reinstall or adjust the unit if it's badly off.

7. Loose or Cracked Drain Pan

The drain pan sits below your evaporator coil and catches water. If the pan cracks or shifts, water leaks right out.

Metal pans can rust and develop holes. Plastic ones might crack from age or a bump.

Inspect your drain pan for:

• Cracks or holes you can see

• Rust on metal pans

• Loose mounting that lets the pan move around

Small cracks might be patchable with waterproof sealant. Big damage usually means you need a new pan.

8. High Humidity Levels in Singapore

Singapore's climate is humid year-round, so your aircon has to remove a lot of moisture. Extra humidity means more water collects inside.

On really humid days, the drain pan might overflow. This is a common occurrence during the rainy season.

Humidity management tips:

• Try a dehumidifier in your room

• Keep the space well ventilated

• Don't set your aircon temperature too low

Some water in the pan is normal in humid weather. But you shouldn't see water leaking out onto your floor or walls.

9. Poor Maintenance Habits

Regular maintenance stops most leaks before they start. If you skip it, minor issues can escalate into larger problems.

Cleaning your aircon regularly stops dirt from building up and causing clogs.

Essential maintenance tasks:

• Clean or swap out filters every month

• Check drain lines for blockages

• Wipe down the outside of your unit

• Book a pro for yearly servicing

Good habits save you money and help your aircon last longer. Additionally, it functions more effectively when it's clean.

10. Old or Ageing Aircon Unit

Older aircons tend to develop leaks. Over time, parts wear out and seals break down.

Metal parts rust and plastic gets brittle. All of this makes leaks more likely as your unit ages.

Age-related leak causes:

• Worn-out seals and gaskets

• Corroded drain pans

• Pumps or motors that are failing

How to Fix a Leaking Aircon: DIY vs Call a Pro?

Some aircon leaks are easy to fix yourself, but others require professional attention. DIY works best for basic cleaning and minor problems, especially if your warranty's already expired.

Safe DIY Fixes You Can Try

Try these first:

• Clean your air filter – Take it out and rinse it with water

• Check the drain pipe – Clear any visible clogs

• Wipe the drain pan – Get rid of dirt or gunk

• Make sure air can flow – Don't block the vents

Regularly cleaning and inspecting your filter and drain line can help prevent leaks.

When to Call a Professional

Call a pro right away if there is a serious issue like:

Situation	Why You Need Help
Water dripping from ceiling	Could be an electrical hazard
Leaks near electrical outlets	Major safety risk
Ice forming on coils	Likely a refrigerant issue
Leaks from more than one spot	Needs expert diagnosis

Serious or risky leaks are best left to a professional. Don't mess with electrical parts or refrigerant yourself.

Professional technicians handle refrigerant, electrical problems, and complex drainage issues safely.

They've got the tools and know-how to fix things you can't see.

If your DIY fix doesn't work in a day, it's probably time to call someone in.

Preventing Future Aircon Leaks

Honestly, the easiest way to avoid leaks is just to keep up with regular maintenance. A little effort now saves you a lot of hassle later.

Clean your air filter every 2-4 weeks. If it gets clogged, airflow drops and the evaporator coil can freeze. When that ice melts, you get water everywhere.

Book a professional service every 3-6 months. In Singapore, routine servicing is key for keeping dirt and algae out of your system.

Don't ignore warning signs:

• Musty smells coming from the unit

• Water pooling under or around the air conditioner

• Gurgling noises from the drain pipes

• Cooling just isn't what it used to be

Check your drain line every month. Pour a cup of water down it—if it doesn't flow, you've probably got a clog.

Consider affordable maintenance packages from reliable aircon companies. These often include filter cleaning, drain checks, and inspections.

Keep the space around your outdoor unit clear. Get rid of leaves, debris, and plants that could block airflow or drainage.

Keep an eye on your home's humidity. High humidity stresses your system and leads to more condensation.

Replace old units before they start giving you trouble. Older aircons are just more likely to leak as parts wear out.

Why Choose a Professional Aircon Technician in Singapore?

Singapore's heat and humidity really put aircon systems to the test. Local technicians know what they're up against and can quickly sort out leaks.

Professional air conditioning technicians have specialized training and experience with these systems. They can pinpoint the cause of your leak and fix it right the first time.

Key Benefits of Professional Service:

• Proper diagnosis – Find the real cause, not just the symptoms

• Quality tools – Access to equipment you probably don't own

• Safety first – No risk of shocks or refrigerant exposure

• Warranty protection – Keeps your warranty valid

At 338 Aircon, our experienced team responds fast to leaking aircon emergencies. We give you fair, upfront pricing—no surprises.

"My air conditioner was leaking badly on a Sunday morning. 338 Aircon came within 2 hours and fixed the blocked drain pipe. Great service and reasonable price!" - Mrs. Tan, Jurong West

Pros also offer advice on upkeep so you can avoid future leaks. They often catch small issues before they become big, expensive headaches.

DIY fixes can sometimes make things worse. Professional contractors keep your system running smoothly and safely in Singapore's tough climate.

When to Replace vs Repair?

Choosing between fixing or replacing your leaky aircon isn't always easy. It really depends on a few big things.

Cost is usually the biggest factor. If repairs cost more than half the price of a new unit, it's probably smarter to replace it.

Age makes a difference. If your ac is over 10 years old, a new one might save you money in the long run.

Older units break down more and use more power.

Constant breakdowns are a warning sign. If you're calling for repairs every few months, think about getting a replacement.

Here's a quick guide to help you decide:

Repair When:	Replace When:
Unit is under 7 years old	Unit is over 10 years old
First major problem	You've had several repairs lately
Repair is less than 50% the cost of new	Repair is more than 50% the cost of new
Still cools well otherwise	Doesn't cool well even after fixing

Energy bills can be a clue. If they're creeping up and maintenance doesn't help, your unit's probably not efficient anymore.

Lots of air conditioner leaking water or condensation usually means bigger issues that might cost more to fix than to replace.

Still unsure? We can provide you with a free quote for the condenser and help you determine what's best for your situation.

Final Thoughts

An air conditioner that is leaking isn't normal, but it's usually fixable. Most water leaks have pretty simple solutions.

Quick action saves money. Water damage to your walls or floors can end up costing way more than the actual repair.

You can handle some fixes yourself:

• Clean dirty air filters every couple of weeks.

• Check if the drain pan is full.

• Wipe up water as soon as you spot it.

When to call a professional:

• Refrigerant leaks (they're a safety risk).

• Frozen coils that keep coming back.

• Clogged drain lines you just can't clear.

• Damaged drain pans.

Don't ignore small leaks. They usually get worse with time.

Water damage sets up the perfect conditions for mold, and that's a real health concern.

Prevention is key. Regular cleaning and yearly maintenance help you dodge most leaks before they even start.

Your air conditioner is working hard to keep you cool. Take care of it, and you'll dodge a lot of nasty surprises and repair bills.

Don't wait until your ceiling stains or your floor warps—book a check-up sooner rather than later. It's a small investment now that can save you a headache (and cash) later.

✅ Need help now? Get same-day aircon servicing and repair from Singapore’s trusted team.

👉 Contact 338 Aircon Today

Frequently Asked Questions

Homeowners have various concerns about their leaking air conditioning units. From brand quirks to health risks and insurance, these common questions address real-life situations you might encounter.

How do I address a leaking Mitsubishi air conditioner unit?

Mitsubishi aircon units leak for the same reasons as any other brand. Clogged drain lines, dirty filters, or a cracked drain pan are the usual suspects.

Start by cleaning your filters and checking the drain pan for cracks. If it still leaks, it's time to call a Mitsubishi-certified technician.

Can a leaking aircon cause mould or health issues?

Absolutely, a leaking aircon can create serious health problems. Water leaks lead to mould, mildew, and sometimes nasty smells.

Mould spores can set off allergies and breathing issues. Clean up water right away, and maybe run a dehumidifier while you wait for repairs.

Why does my aircon leak only at night or after turning off?

If your air conditioner leaks at night, it's due to temperature changes that lead to extra condensation. When the unit shuts off, any frozen coils can melt and overflow the pan.

This usually happens if filters are dirty or refrigerant is low. Check your filters first, then call a technician if it keeps happening.

Can ceiling-mounted aircon units leak more than wall units?

Ceiling units seem to leak more because gravity pulls water straight down onto your floors or furniture.

But honestly, both types leak at about the same rate when there's a problem.

The real difference is you'll notice ceiling leaks faster since water drips right into your living space.

Is it normal for some water to drip from my aircon?

A little water under the outdoor unit is normal, especially on hot days. That's just condensation from cooling.

However, if you notice large puddles or water coming from the indoor unit, something is wrong. Call a repair service if the issue persists.

Can high humidity in Singapore make aircons leak more often?

Yes, Singapore's crazy humidity means your aircon pulls even more moisture from the air. When there's lots of humidity, water can pile up and overflow the drain pan.

Regular maintenance is even more important in humid places. Keeping filters clean and drain lines clear helps your system handle all that extra moisture.

Will insurance cover aircon water damage in Singapore?

Most home insurance policies in Singapore do cover sudden water damage from aircon leaks. However, if the damage results from neglect or a slow, unnoticed leak, you may not be covered.

Check your policy and take photos of any damage. Contact your insurer immediately if leaks damage your property.

How long can I run a leaking aircon before damage occurs?

You really shouldn't run a leaking aircon. It can damage the unit and exacerbate the issue.

Running it could flood your home, fry electrical parts, and rack up repair costs. Just turn it off and call a technician.

What should I do if my aircon is leaking onto my neighbour's unit?

Turn off your aircon right away and call a repair service. Wipe up any water and let your neighbour know what happened.

You might be responsible for their property damage, so document everything and contact your insurance if you need to.

Are certain aircon brands more prone to leaking?

All aircon brands can develop leaks if proper maintenance is neglected. Leaks typically occur due to clogged drain lines, dirty filters, or damaged parts—not necessarily because of brand defects.

Here's how to prevent future issues with the aircon unit: clean your unit regularly and call in a pro for maintenance. Honestly, just stick with reputable brands that offer solid warranty coverage.