What Happens If My Drain Pan Is Clogged?

Unbeknownst to many homeowners, an air conditioning unit is a complex grouping of parts and systems that work together to give you cool air on-demand, year-round. One of the components that is very rarely thought of, however, is your system's drain pan. As your air conditioning system runs, it creates condensation that drips down your unit and collects in the drain pan, which the system then disperses outside by way of a drain pipe.

Unfortunately, this drain pipe can become clogged in any number of different ways, such as dirt and debris that finds its way into your pipes, or by stray grass clippings and even rodents. If it stays clogged, water can build up and cause any of the problems outlined below. If your drain line is clogged, contact an HVAC company to schedule air conditioner repair as soon as possible.


Most AC units are metal, which means prolonged contact with any amount of standing water can create premature rust and corrosion on its parts. This will, in turn, cause those parts to break and clink around inside your unit and ductwork, potentially causing major issues to your HVAC system. If left unattended, it can even cause your entire system to need to be replaced, which can cost thousands of dollars.

Water Damage

Just because your drain pan fills up doesn't mean the water stops flowing, so eventually, the water that is in your drain pan will spill out and cause significant water damage to the area around it. This can result in mold building up on your walls or even leaks developing inside your home. At that point, it becomes more than an AC repair issue; you'll most likely need to hire a contractor to perform some general construction work to repair sheetrock and possibly a few electrical components as well.


The most immediate opportunity for mold to appear in your home is anywhere a significant amount of standing water is left unattended, such as an overflowing drain pan. Subtly though, the humidity in your home will also increase as a result of your air conditioning system not functioning properly, which means mold can develop inside your ductwork or near the vents, causing health problems for your family. Check your drain pan often, and if you find that it's been clogged, contact an HVAC technician to perform any air conditioning repair that needs to take place.

About Me

Perfecting My Home HVAC System

After dealing with almost constant air conditioner and furnace failures, I realized I might not be doing my part to keep my systems clean and operational. To sort out the issues, I turned to a professional repairman for help. He explained that since I wasn't changing the filters regularly, there was no telling what would happen. I learned how to clean evaporator coils, replace filters, and even sort out power failures on my own. I want other people to experience the confidence and comfort that comes along with protecting your own HVAC system, so I put up this blog.