If you’ve walked past your indoor unit and noticed a puddle, you’re not alone—and you’re probably wondering, “Why is my HVAC leaking water?” It’s a common issue for homeowners in Manassas, VA, especially during seasonal changes. Whether it’s your AC leaking water, your furnace dripping, or water pooling near your system, it’s important to know what’s going on and what to do next.
In this post, we’ll break down the most common reasons your AC unit is leaking water, what risks it poses, and how to prevent future issues.
Common Reasons Your AC Is Leaking Water
1. Clogged Condensate Drain Line
The most frequent cause of AC leaking water inside is a clogged drain line. Over time, dust, dirt, mold, and algae can build up, blocking the path that allows condensation to drain. When that happens, the water has nowhere to go—so it backs up and leaks into your home.
Please do us a solid and avoid DIY drain cleaning with harsh chemicals. These can damage your HVAC system. It’s safer (and smarter) to call a professional — that’s us!
2. Dirty Air Filter
A clogged air filter restricts airflow, which can lead to the evaporator coil freezing. When it eventually thaws, the excess water may overflow the drain pan. This is a top reason for AC leaking water on the floor or water dripping from the AC indoor unit.
3. Damaged or Rusted Drain Pan
If your system is older, the drain pan might be rusted or cracked. Even small leaks can cause major damage to floors or ceilings if left untreated.
4. Low Refrigerant Levels
When refrigerant is low, it causes the evaporator coil to freeze. Just like with dirty filters, the melted ice can flood your system’s drain pan and result in water leaking into your home.
Why Is My Air Conditioner Leaking Water Inside the House or Apartment?
If your air conditioner is leaking water inside, especially in an apartment or upstairs unit, this can cause structural damage, water stains, and mold. Whether it’s dripping from the ceiling or pooling under the unit, don’t wait. The longer you delay, the more costly the cleanup and repairs can be.
Why Is My Furnace Leaking Water?
If you notice water around your furnace, especially when the heat is on, a few culprits could be to blame:
- Condensation from a high-efficiency furnace that isn’t draining properly
- A malfunctioning whole-home humidifier connected to your furnace
- Leaky or cracked drain lines or internal piping
Wondering “Is a furnace leaking water dangerous?” While not always an emergency, it can cause rust, mold, or even system failure. It’s best to call for a professional inspection right away.
Why Is My Window AC Leaking Water?
For homeowners with window AC units, a common issue is improper installation. If the unit isn’t tilted slightly outward, condensation can collect inside and leak into your home.
A simple leveling adjustment may fix the problem—but check to ensure the drain isn’t blocked, too.
How to Fix an Air Conditioner Leaking Water Inside
Here are a few steps you can take if you notice your AC leaking water:
- Turn off your system to prevent further damage. (This is always number one!)
- Replace your air filter if it’s dirty.
- Check for clogs in the condensate drain (if visible).
Call an HVAC professional to inspect the system fully.
While not all leaks are emergencies, water in or around your HVAC system should always be checked promptly to avoid bigger—and wetter—problems.
Preventing Future HVAC Leaks with Seasonal Maintenance
The best way to avoid an HVAC leaking water on the floor or AC leaking inside is through routine maintenance. During a seasonal tune-up, our certified technicians will:
- Flush and inspect the drain line
- Check refrigerant levels and pressure
- Clean filters, coils, and pans
- Test system performance
This proactive approach keeps your home dry, your system efficient, and your energy bills lower.
What If the Leak Is Ongoing or Getting Worse?
If you’ve already tried cleaning or replacing your filter and the issue continues, don’t wait. Leaks that go unchecked can lead to mold growth, water damage, and system breakdowns. And trust us—a flooded HVAC closet during peak summer heat is not something you want to deal with.
Professional HVAC Help in Manassas, VA
At Shaw Services, we’ve been helping homeowners in Northern Virginia keep their homes dry and comfortable since 2013. Whether your air conditioner is leaking, your furnace is dripping, or you just want peace of mind before the next season rolls in—we’re here for you.
📞 Call us today or book a visit online. Let’s take the guesswork out of HVAC and get your system back to leak-free comfort.