AC Repair · Lake Jackson, TX

AC Leaking Water Inside the House — Lake Jackson, TX

Water dripping from your AC unit isn’t normal. Here’s what’s causing it and when to call a technician.

Why Is My AC Leaking Water Inside the House?

Short answer: Water leaking from an AC unit indoors is almost always caused by a blocked condensate drain line, a frozen evaporator coil that’s thawing, a cracked or overflowing drain pan, or a disconnected drain line. In Lake Jackson’s high-humidity climate, condensate drain clogs are the single most common cause. Left unaddressed, indoor water leaks can cause mold growth, ceiling damage, and electrical hazards.

Central air conditioners produce condensation as part of the cooling process. That moisture collects in a drain pan and flows out through a condensate drain line. When anything interrupts that flow, water backs up and can overflow or drip into your home. Understanding the specific cause helps you decide whether it’s a DIY fix or a job for a professional.

4 Most Common Causes of AC Water Leaks Indoors

Clogged Condensate Drain Line

Algae, mold, and debris build up inside the PVC drain line over time — especially in humid Gulf Coast summers. When the line is blocked, water backs up into the drain pan and overflows. This is the most frequent cause in the Brazoria County area.

Frozen Evaporator Coil Thawing

If your AC ran with restricted airflow (dirty filter, closed vents) or low refrigerant, the evaporator coil can freeze. When the system shuts off or the ice melts, large amounts of water drip faster than the drain pan can handle. You may notice ice on the unit before the leak appears.

Cracked or Rusted Drain Pan

Most air handlers have a primary drain pan and a secondary overflow pan. If the primary pan cracks or corrodes through — common in older systems — water bypasses it entirely and drips into the air handler cabinet or ceiling space below.

Disconnected or Improperly Pitched Drain Line

A drain line that slopes upward instead of downward, or one that has come loose from the fitting, won’t drain at all. This is often a post-installation or post-maintenance issue that requires reconnecting and re-sloping the drain piping.

Less common causes include a dirty air filter severely restricting airflow, low refrigerant charge causing abnormal coil temperatures, or an incorrectly sized system that short-cycles and produces excess condensation.

What Happens If You Ignore an AC Water Leak?

Risks of leaving a water leak unaddressed

Mold and mildew growth — Lake Jackson’s humidity means mold can establish in as little as 24–48 hours in wet drywall or insulation
Ceiling and wall damage — water saturating drywall leads to staining, bubbling, and eventual structural deterioration
Electrical hazard — water dripping near wiring, capacitors, or the blower motor creates a shock or fire risk
Secondary drain pan overflow — if the secondary float switch isn’t present or fails, water can overflow for hours undetected
Compressor damage — if the root cause is low refrigerant, running the system continues to harm the compressor

Turn off your AC at the thermostat (and at the breaker if water is actively dripping near electrical components) until the source is identified and corrected.

What You Can Check Yourself vs. What Needs a Technician

✓ Safe to check yourself

Replace the air filter (if visibly dirty or clogged)
Pour 1 cup of distilled vinegar into the condensate drain line access port to flush minor algae clogs
Use a wet/dry vacuum on the drain outlet outside to attempt clearing a soft blockage
Open all supply and return vents to restore proper airflow
Check the secondary drain pan — if it has water, the primary is already overflowing

✗ Requires a technician

Persistent drain clogs that don’t clear with vinegar or vacuuming
Any sign of a frozen evaporator coil (ice on refrigerant lines, reduced airflow)
Cracked or rusted drain pan replacement
Disconnected or re-pitched drain line reconnection
Low refrigerant diagnosis or recharge
Water near electrical components or inside the air handler cabinet

If the DIY steps above don’t stop the leak within 15–20 minutes, or if water is active inside the air handler cabinet, turn the system off and call a technician.

Typical Repair Cost Estimates

The cost depends on the underlying cause. These are general market estimates for the Gulf Coast Texas region — not our company’s guaranteed pricing. Your actual cost will depend on system age, access, parts, and labor time.

Repair Type	Estimated Market Range
Condensate drain line flush / clear	$75 – $200
Drain pan replacement (secondary pan)	$200 – $450
Drain line reconnection and re-pitch	$100 – $250
Evaporator coil inspection + freeze diagnosis	$100 – $200 (service call)
Refrigerant recharge (if low refrigerant found)	$200 – $600+ depending on refrigerant type
Full evaporator coil cleaning	$150 – $400

These are market estimates based on typical Gulf Coast Texas pricing as of 2024–2025. They are not a quote from our company. Contact us for an accurate diagnosis and price for your specific system.

AC Leaking Water in Lake Jackson?

Our technicians serve Lake Jackson and the surrounding Brazoria County area. Call now to schedule a diagnostic visit.

Call (979) 258-5550

Frequently Asked Questions

Can I run my AC if it’s leaking water inside?

It’s best to turn the system off until the cause is identified. Running the AC when the evaporator coil is frozen can damage the compressor. If water is near any wiring or electrical components inside the air handler, turn off the breaker — don’t just use the thermostat.

How do I know if my condensate drain line is clogged?

Signs include water dripping from the indoor air handler, the secondary drain pan filling with water, a float switch shutting the system off, or a musty smell from the vents. You can also check the drain outlet outside — if no water drips during normal AC operation on a humid day, the line may be blocked.

Why does my AC leak more on very humid days?

On high-humidity days, your AC removes significantly more moisture from the air, producing a larger volume of condensate. A drain line that’s partially clogged may handle normal condensate flow but overflow when condensate volume increases on extremely humid Gulf Coast summer days.

What’s the difference between a primary and secondary drain pan?

The primary drain pan sits directly beneath the evaporator coil and drains continuously. The secondary (overflow) pan sits underneath the entire air handler as a backup — it only collects water if the primary pan overflows or leaks. Many systems have a float switch in the secondary pan that shuts the AC off when water is detected.

How often should the condensate drain line be cleaned in Lake Jackson?

In the Gulf Coast climate, annual cleaning is a minimum — twice a year (spring and midsummer) is more appropriate given the long cooling season and high humidity that promotes algae growth. Some homeowners pour distilled vinegar into the drain access monthly as a preventive measure.

Is AC water damage covered by homeowners insurance?

Coverage depends on your specific policy and the cause of damage. Sudden and accidental water damage is often covered; damage from a slow leak that was “neglected” may not be. Contact your insurance provider directly — we can’t advise on your coverage, but documenting the repair promptly supports any potential claim.

Get Your AC Leak Diagnosed in Lake Jackson

Serving Lake Jackson, Clute, Richwood, Freeport, Angleton, and the surrounding Brazoria County area.