It’s a hot summer in Ontario. As you pass your air conditioner, you see a puddle starting on the floor. Your first thought? Panic. But perhaps one of the most frequent issues faced by homeowners all over the GTA, Mississauga, Oakville, Hamilton and Milton is ac leaking water.
The good news? There are some causes that can be tackled on your own. The not-so-good news? If you don’t repair an AC leak, the situation can very easily get out of hand, causing water damage, mold growth and costly repairs later. So what do you need to know & do right now?
Why Is My AC Leaking Water? Understanding the Basics
Your air conditioner does more than cool down the air, it dries it out as well. The warm and moist air cools as it comes in contact with the cold evaporator coil inside the unit, and the condensation begins (like a cold glass of water on a hot day). This water is stored in the drain pan and drains through the condensate drain line.
If any of those things gets broken, you’ll get a leaking air conditioner. The problem is, it’s not necessarily a crisis, but it’s always a problem.
Top 6 Causes of a Leaking Air Conditioner (And What to Do)
- Clogged Condensate Drain Line
- Dirty or Clogged Air Filter
- Frozen Evaporator Coil
- Cracked or Rusted Drain Pan
- Low Refrigerant Levels
- Improper Installation or Oversized Unit
1. Clogged Condensate Drain Line
This is the number one reason for ac leaking water in Canadian homes. With time, the dirt, dust, algae and mould accumulate in the drain line that restricts water flow. The backed up water has no place to go, and overflows around the unit.
The solution you can try: Just pour one cup of white vinegar into the access point in the drain to clear up the buildup. A wet/dry vacuum can be used at the end of the drain pipe to remove the blockage as well. If after a few tries it still doesn’t open, then a professional will be called to stop it from causing any water damage at all.
2. Dirty or Clogged Air Filter
A dirty air filter can cause the air flow to be limited over the evaporator coil. In the absence of warm air blowing over it, the coil will become too cold and freeze. As this ice gradually thaws it releases much more water than the drain pan can hold and you have a leak.
What might be done: See if the air filter needs to be changed or replaced. Filters should be changed every 30-90 days for most Canadian residences, particularly in the summer when filters are in use for extended periods of time.
3. Frozen Evaporator Coil
Other reasons for the evaporator coil to freeze up include low refrigerant levels, or blocked vents. Then, when it thaws the overflow can be viewed as a significant ac leakage repair task even though the repair may be relatively easy.
Signs to look for: Decreased cooling, frost on unit or if ac fan is not working correctly.
What you can do: Set the air conditioner to off, and allow it to thaw for several hours. To hurry the process, switch to “fan only” mode. Never use ice picks to chip the ice. If it continues to freeze, check the cause – it’s a refrigerant problem and a licensed HVAC technician will be able to take care of it.
4. Cracked or Rusted Drain Pan
The drain pan is installed under your indoor air handler to collect the condensation. In older units, these pans (sides) rust or crack over time and no longer contain water. It is very common in older central air conditioning units in houses throughout the GTA.
Troubleshooting steps: Check for any cracks or rust on the pan. A pan can sometimes be temporarily patched with a waterproof patching compound for the minor cracks, but the pan should be replaced if it is damaged. This is something that you need to get your local ac repair service team to do.
5. Low Refrigerant Levels
If there is a low in the refrigerant, the pressure will decrease within the system and the temperature of the evaporator coil will drop lower than normal. This can cause the ice to freeze and later melt, causing flooding. Also, you might notice ac is making loud noise (hissing or gurgling) or that your central ac not cooling your home properly anymore.
What you can do: Nothing by yourself. A licensed HVAC technician is required to perform work on refrigerants. Don’t wait to do this, a refrigerant leak is not good for your system or the environment.
6. Improper Installation or Oversized Unit
Water may not drain properly if your AC wasn’t installed properly with the leveler. If it is too large it may short cycle (turn on and off too often) resulting in too much condensation for the drainage system.
The steps you can take: If you just had a new ac installation and the leaking began shortly after, then contact the installing company right away. If they don’t respond, contact a trusted hvac repair professional.
Is a Little Water Normal?
It’s okay if there is a little condensation, it drips from your outdoor unit during hot humid days. If you see pools of water inside the house, big puddles around the indoor unit or water stains on the walls or ceiling, it’s not normal.
The humidity in the Canadian summer is a serious thing, particularly in the Niagara, Hamilton and lakeshore areas. The air conditioning system has to work harder in drier climates than here and this means you will often see these drainage problems here that you may not see or hear in drier climates.
What Should You Do Right Now If Your AC Is Leaking?
Here’s a quick step-by-step for ac troubleshooting when you spot a leak:
- Turn off your AC at the thermostat and the circuit breaker right away. Running a leaking unit can cause electrical damage.
- Soak up standing water using old towels. This protects your floors and subfloor.
- Check your air filter. If it’s grey and clogged, replace it.
- Inspect the drain pan for visible cracks or rust.
- Try clearing the drain line with vinegar or a wet/dry vac.
- Call a professional if you can’t find the cause, if the leak is large, or if the problem returns.
Ensure that water is not left standing. Health Canada advises us that if there are moisture issues in your home, it can cause real risks to your family’s respiratory health within 24-48 hours, with the risk of mold forming.
When to Call for Emergency AC Repair
In some circumstances, the services of a professional are needed immediately, not tomorrow or next week. If you’re in need of hvac service near me or emergency ac repair, you’ll want to look for the following reasons:
- Water is leaking near electrical components
- You smell something musty or see visible mould
- The leak is large and spreading fast
- Your AC isn’t cooling at all despite running
- You suspect a refrigerant issue (hissing noise, frost on lines)
- You’ve tried the basic fixes and nothing has worked
In this scenario, you also might require a 24 hour plumber or emergency plumber in case the leak has damaged your drainage lines or plumbing system, particularly in finished basements.
How Often Should You Service Your AC to Prevent Leaks?
The easiest method to prevent leaking air conditioners is to do routine maintenance. The HVAC experts suggest that it is best to book AC services near me at least once annually—preferably in the spring, prior to turning on the heating system for summer. During a tune-up, the evaporator coils are cleaned, the drain line is flushed, the amount of refrigerant is checked and the drain pan is inspected. It is a low cost measure which avoids largescale, costly surprises.
For mini splits ac and mini ductless ac systems the same rules apply, although they are more efficient than other systems they are not maintenance free.
Can a Leaking AC Damage Your Home?
Yes and the damage can become expensive very quickly.
Even a slow leak can affect:
- Hardwood flooring
- Basement ceilings
- Insulation
- Drywall
- Electrical systems
Often, many people in the GTA assume leaks in their air conditioning system are plumbing problems since the water may be found in their basements or utility rooms.
For this reason, BOS Plumbing and Drains will tackle HVAC-related water problems along with plumbing system inspections if necessary.
Signs You Need Emergency AC Repair
Sometimes an AC leak is a symptom of a larger HVAC failure.
Call for same-day service if you notice:
- AC fan not working
- Central AC not cooling
- Loud banging or grinding noises
- Warm air coming from vents
- Water pouring from indoor unit
- Burning smells
- Frozen evaporator coils
- Repeated shutdowns
These problems can worsen quickly during peak summer temperatures.
Trust BOS Plumbing and Drains for AC and Plumbing Emergencies Across the GTA
You’re not sure who to contact if your air conditioner is leaking, BOS Plumbing and Drains will help you! We uniquely understand the challenges of Ontario homes and climate with over 20 years of service to homeowners and businesses in the Greater Toronto Area.
We offer fast, reliable service across:
- Mississauga
- Oakville
- Hamilton
- Milton
- Niagara
- Cambridge
- And the whole GTA
Whether you need a same day plumber, a commercial plumber for a business property, or 24 hour plumbing service for a plumbing emergency that can’t wait, our licensed team is ready to respond. We handle everything from ac repair and service to full plumbing repair, drain cleaning, and emergency calls that most companies won’t touch after hours.
A Hamilton plumber! A plumber at Oakville Ontario or plumber at Milton? A single call to BOS Plumbing and Drains ensures that you get a certified expert at your doorbells in no time.
We’re not just about to fix your plumbing leak, we’re about to become your long-term home comfort partners. Whether you need aircon servicing near me, after hours plumbing services or plumbing emergency services, we have seen it all, and fixed it all.
Make an appointment with BOS Plumbing and Drains today, for same-day services and for trustworthy pricing and services that have been around for twenty years in the GTA.
Final Thoughts
If you’re leaking air conditioner water, it’s not something you should shrug off, but it’s also not necessarily a cause for concern. There are numerous causes that can be addressed with simple measures such as replacing a filter, cleaning a drain line, replacing a drain pan and more. The most important thing is to take prompt action, to prevent water damage to your home and to seek professional help when the repairs are more than the usual.
When a plumbing issue arises, Mississauga, Oakville, Hamilton, Milton and all of the GTA homeowners rely on BOS Plumbing and Drains. Problems don’t always start right.But a little problem can grow into a big issue.
People Also Ask
1. Can I run my AC if it’s leaking water?
No. Turn it off immediately. Running a leaking AC unit can cause electrical hazards, worsen the leak, and lead to mould growth in your home.
2. How much does AC leakage repair cost in Canada?
It varies. Clearing a clogged drain line is relatively affordable, usually under $150–$200. Replacing a drain pan or fixing a refrigerant issue can range from $200 to $600 or more, depending on your system.
3. Why is my air conditioner not working and leaking at the same time?
This is often a frozen evaporator coil. The unit can’t cool properly because the coil is iced over, and when it melts, it leaks. Check your filter first, then call a technician if it keeps happening.
4. How do I know if my AC problem is a plumbing or HVAC issue?
Sometimes it’s both. If the condensate drain line connects to your home’s plumbing system and there’s a clog deeper in the line, you may need both an ac fix and help from a residential plumber to clear the plumbing system properly.
5. Is AC leaking water covered by home insurance in Canada?
It depends on your policy and the cause. Sudden and accidental water damage is often covered, but gradual leaks due to lack of maintenance typically are not. Check with your provider.