In addition to regulating your indoor temperature, the air conditioner in your Houston, TX home also offers limited air filtration and humidity control. When the outdoor temperature is at its highest, some air conditioners leak small amounts of water due to increased workload and the production of excess condensation. However, although a small water leak isn’t always cause for immediate concern, certain AC leaks are. Read on to learn several causes of air conditioner leaks and the best steps for resolving them.

Normal AC Leakage: What It Is and What Causes It

During the typical cooling cycle, your air conditioner extracts warm air from the interior of your home and passes it over its evaporator coil. The icy refrigerant within this coil extracts the air’s heat. Once chilled, this same air is then distributed throughout the building.

Hot refrigerant travels to the outdoor condenser unit as a high-pressure gas. As it condenses, condensation is released and funneled through your air conditioner’s condensate drain line, into the drain pan, and out of your home. The outdoor air might be especially humid or outdoor temperatures may be especially high. If so, greater-than-normal condensation can lead to visible pools of water at the exterior of the building or just beneath your air handler.

Secondary Condensate Drain Pans

Normal AC leaks are sometimes found at secondary condensate drain pans rather than the building exterior. Frequently required by building code, these pans limit the risk of property damage by catching any overflow missed by primary pans. If you have one, you’ll likely find yours beneath your indoor air handler or furnace and connected to piping that ends just outside.

Secondary drain pan leaks can prove problematic over time. If secondary drain pans overflow, pooling water can cause flooring damage, sub-floor damage, and problems with warping, mildew, and mold at and behind baseboards and drywall. They can also create the risk of slip and fall accidents if they aren’t caught and corrected early on.

If your air conditioner regularly experiences “normal” leaks on hot, humid days, it may be too small for its intended service area. Also, there may be other sizing, age-related, or air-balancing issues. Many “normal” AC leaks are only “normal” in the sense that aren’t indicative of functional cooling equipment problems.

Blocked Condensate Drains

Blocked condensate drain lines and drains are among the most common causes of AC leaks. These issues often develop in air conditioners that haven’t received professional, pre-season maintenance. During long, seasonal periods of dormancy, air conditioners can develop overgrowths of bacteria and algae in high-moisture components. Bacterial sludge known as biofilm and copious collections of algal blooms inhibit the flow of water. This causes condensate to back up into primary and secondary drain pans. With nowhere to go, collected condensation eventually spills out onto floors.

If your air conditioner is leaking water and hasn’t been professionally serviced in more than one year, turn it off and schedule a tune-up. Leaks resulting from poor AC maintenance are often paired with other maintenance-related concerns. Continuing to use your AC could result in:

  • Excess indoor humidity
  • Unpleasant odors during AC operation
  • Short cycling or overheating
  • Premature equipment failure

Having your block condensate line cleared and catching up with all manufacturer-recommended maintenance will reduce operational stress, improve the efficiency of your cooling system, and limit your total repair costs.

Dirty HVAC Air Filters

Another common cause of AC leaks is dirty air filters. Although HVAC air filters provide modest indoor air quality (IAQ) benefits, these components primarily exist to protect heating and cooling equipment. They optimize operating conditions by minimizing airborne particulates like:

  • Pet hair
  • Textile and carpet fibers
  • Dust
  • Lint
  • Dander

Without a clean filter installed, airflow throughout your HVAC system will gradually decline. This keeps air from moving over and through evaporator coils as it should and inhibits heat transfer. As a result, cold refrigerant remains frosty and eventually causes evaporator coils to ice over. When your frozen evaporator coil defrosts, you’ll find standing water just beneath your air handler.

If your air conditioner is both leaking water and short cycling, check your filter. To prevent filter-related icing, check your HVAC air filter monthly by holding it up to the overhead light. If light cannot pass through a filter’s mesh due to built-up debris, air cannot pass through it either. Most HVAC equipment manufacturers recommend changing these components every 30 to 90 days.

Disconnected Drain Lines

Your AC drain line is either a thin, copper pipe or a white PVC pipe. Drain lines are accessible just near indoor air handlers. Unfortunately, this also places them in close proximity to HVAC air filter housing. If you recently changed your HVAC air filter for the very first time, there’s a slight possibility that you knocked the drain line’s connection loose. Drain lines can also be disconnected due to improper installation, insufficient AC maintenance, and gradual, weight-related loosening. When drain lines are weighed down by heavy accumulations of biofilm and algae, this weighty material can wear their connections down.

Although much less common than dirty air filters and blocked condensate drains, a disconnected drain line could be the source of your AC leak. This is the most likely cause of AC leaking when there are larger, fast-spreading pools of standing water indoors.

Refrigerant Leaks

During recharge service, AC refrigerants are often paired with oils. Some refrigerants are additionally mixed with yellow-tinged dyes to enhance their visibility.

You might have a refrigerant leak if the water in or around your drain pan is oily. You can also check your AC evaporator coils for yellow, light-brown, or champagne-like bubbles. When AC refrigerant leaks are left unchecked, homeowners often hear loud hissing or screeching sounds coming from their outdoor condenser/compressor units.

Much like dirty HVAC air filters, low refrigerant can cause icing at evaporator coils. As this ice melts, puddles form just beneath furnaces or air handlers.

Why Suspected Refrigerant Leaks Are Serious

In addition to exposing building residents to toxic chemicals, refrigerant leaks take a major toll on AC compressors. Your air conditioner’s compressor operates under extreme pressure all of the time. It pumps refrigerant to and from your indoor air handler by alternately pressurizing and depressurizing it. With increasingly less refrigerant to move, your AC compressor could fail or collapse. Thus, if you think you have a refrigerant leak, it’s best to shut your cooling system off and schedule emergency AC repair service.

Cold Temperatures

Having small amounts of water drip from your air conditioner during late summer or early fall is fairly normal. When outdoor temperatures drop, active air conditioners can ice over. Your evaporator coil could become frosty and thaw out if you operate your AC on days when the outside temperature is just 60 degrees Fahrenheit or lower.

We help homeowners in Houston, TX keep their air conditioners in top condition year-round. We offer outstanding heating, cooling, electrical, and indoor air quality services. We also provide smart thermostats, landscaping, and HVAC preventative maintenance plans. To schedule an appointment, contact Mackey Services now.

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