Isn’t it funny how the presence of water can cause such a variety of reactions in different contexts? On a hot July day, water seems cool and inviting when it’s in your backyard pool. It may even be a welcome relief when it’s falling from the sky. But when you find a puddle of water on the floor of your mechanical room, it’s a scary sight and a source of anxiety. Your AC is leaking water. Now what?
First of all, take a breath and relax. There are a number of possible causes for an AC leaking water, and many of them are not difficult or expensive to fix.
However, it’s important to act quickly, because leaking water can cause expensive damage to your walls, ceilings, floors and furnishings. And there is one possible cause of AC leaking water that can cause your air conditioner’s compressor to fail. When that happens, you might find yourself having to replace your unit.
What to do first: look for frozen coils
When you discover that your AC is leaking water, the first thing to do is take a look at your evaporator coil. That’s the part of your indoor air handling unit that looks (as the name implies) like a coiled tube with fins.
Found it? Is it covered with ice? If so, turn off the unit right away. That ice should not be there and puts your system in danger of failure. The puddle of water on the floor is probably coming from that melting ice. This is one case when your AC leaking water can be a serious problem.
The next step is to call a qualified HVAC professional to diagnose the cause of the frozen coil as soon as possible. A frozen AC coil is not a problem you want to tackle yourself.
IMPORTANT: Never try to chip away the ice with a sharp object! You can damage the sensitive coil fins.
If you’re lucky, it might still turn out to be a simple fix like a clogged air filter that caused your evaporator coil to freeze up. Or you could have other system problems that are impeding air flow, leading to frozen coils and ultimately your AC leaking water.
Related article: Top 5 Causes of Frozen AC Coils
Even if your coil is not frozen, it’s a good idea to turn off the unit to prevent water damage in your space. That’s especially true if your unit is on the roof or an attic or crawl space: you want to avoid damage to walls and ceilings from dripping water.
Check out 4 more common causes of an AC leaking water
1. Dirty coils
When AC maintenance has been neglected for a while, it’s common to find a coating of dust and grime on the AC coils. When condensation collects on the outside of the evaporator coil (which is normal), it can’t flow down the coil and into the drain pan as it should, because all that dirt impedes the flow. Moisture can become trapped and then drip onto the floor.
If this turns out to the cause of your AC leaking water, consider yourself lucky. All your need to do in this case is have your coils thoroughly cleaned.
Related topic: AC Coil Cleaning: How to Tell When You Need It
If you hadn’t discovered the dirty coils due to your AC leaking water, the problem could have gotten much worse. The grime on the coils can accumulate to the point where the coils actually become corroded. Then you could be facing refrigerant leaks and possibly having to replace the entire coil.
2. Damaged insulation
Insulation on your coils is supposed to keep the accumulated condensation flowing down the coil. However, when that insulation gets damaged with cracks or holes, water can drip from the coil instead of flowing as it should. The result: your AC leaking water and possibly damage to your space if you don’t notice the problem right away.
In this case, you’ll need a professional to repair or replace the damaged insulation.
3. Disconnected drain line
This is a problem that can occur because of poor installation practices. If your AC’s drain line that drains away condensation wasn’t attached correctly, it can become disconnected and lead to an AC water leak. It might have caused a big mess, but the fix isn’t a big issue.
However, to prevent your AC leaking water in the future, be sure you’ve got an experienced HVAC professional making the repair.
4. Clogged drain line or trap
Here’s another problem that crops up when your unit is dirty from lack of maintenance, and can lead to your AC leaking water.
The condensation collected by your air conditioner carries the dust and debris into your drain line and your drip pan. Eventually, the drain line can clog, causing water to back up and eventually leak. The same thing can happen in the drain pan: dust can clog the drain, causing the pan to overflow.
Once again, your system just needs a good cleaning (after you clean up the water from the leak). One danger here is the damage that can happen to your walls and ceilings from the air conditioner water leak.
However, you should also know that debris coating your system’s parts also causes it to lose efficiency. As a result, your unit has to run longer and work harder to cool your space, which causes increased wear on the parts and can lead to more repair issues. That’s an important reason why AC preventative maintenance is so important.
Learn more about AC maintenance and how to get the right plan for your needs from this helpful guide to HVAC Preventive Maintenance Contracts: How to Find The Right One For Your HVAC Infrastructure.