Water can sometimes leak out of your outdoor AC unit, which usually isn’t anything you need to worry about. However, if the indoor part of your AC system starts leaking, it usually indicates that there’s some issue with the condensate drain that is preventing water from draining away as it should. In this article, we’ll provide an overview of how an AC condensate drain works and what issues can cause it to start leaking.
An Overview of Your AC’s Condensate Drain System
Every type of air conditioning system causes some amount of condensation. That’s why you’ll often see a wet spot under the front of your vehicle when you’ve had the AC running. The easiest way to understand why it happens is to think about how condensation forms and causes water to bead up on a glass of cold water in hot weather. The evaporator coil in an AC system is extremely cold, which results in moisture condensing on the cold when warm air hits it.
A central AC system needs some way to get rid of all of the water that forms, which is where the condensate drain comes into play. The condensate drain system consists of PVC drain pipes that are connected to a drain pan located underneath the evaporator coil. In many cases, the drain pipes then connect to the home’s plumbing or lead to a floor drain. Some AC systems instead have the drain pipes run outside through an exterior wall. If the indoor part of your AC system is in the crawl space, your AC likely has a condensate pump that moves the water outside since it can’t drain away naturally due to gravity.
Clogged Pipe or Drain Pan
Mold, mildew, algae, and slime often form within a condensate drain system over time, which can lead to a clog in the drain pipes or sometimes in the drain pan. Dust and debris can also sometimes end up causing a clog. Just like when there’s a clog in your plumbing, a clog in the condensate drain system means the water that collects in the drain pan has nowhere to go. The result is that the pan can eventually overflow and lead to the water leaking out of the AC system.
Overcoming a clog isn’t always easy, especially if the drain pipes connect to your plumbing. In this case, you’ll need to have AC technicians take the pipes apart so that they can unclog the pipes. The air handler compartment on many AC systems is fully sealed, which means a technician will also need to partially dismantle it to access the drain pan.
Damaged Drain Pan
Older AC systems often have a metal drain pan, which can end up rusting and eventually leaking. This issue is why most AC manufacturers switched to using plastic drain pans. Plastic pans are more durable and usually last for the life of the AC system. Nonetheless, the plastic can sometimes end up cracking, allowing water to leak out of the pan.
An AC technician can sometimes repair a leaky plastic pan by patching the cracks, but this doesn’t always work. If the pan can’t be repaired or you have a metal pan that’s rusted through, you’ll need to have it replaced. This is sometimes a fairly easy job, but there are times when the only way to do it is to disconnect and remove the evaporator coil. In this case, the job will take longer and require much more work since technicians will need to first drain and recover the refrigerant before they can disconnect the refrigerant lines from the evaporator coil. Once they’ve replaced the pan, they’ll then need to braze the line set back onto the coil and then recharge the system with refrigerant.
Loose or Damaged Drain Pipe
If you see water around the indoor part of your AC system but it isn’t dripping out of the air handler, it’s likely that one of the drain pipe connections is loose or a pipe is cracked. In this situation, a technician will just need to take the pipes apart and re-glue the loose joint or replace the damaged pipe.
Failed Condensate Pump
If your AC has a condensate pump, it could be leaking because the pump has failed or isn’t receiving power due to an electrical issue. In this case, a technician will need to check if the pump has power and then either repair or replace it if it’s malfunctioning or has failed.
My Guy Heating and Air, LLC provides expert air conditioning and heating services throughout the Longmont, Mead, and Firestone areas, and our team can help with any issues your HVAC system has. We repair all makes and models of AC and heating equipment, and also offer professional maintenance and installation services for residential and commercial customers. To overcome issues with your AC leaking, contact us today to schedule a service call.
