San Antonio · Frozen AC Coil Repair Repair · Family-Owned Since 1996
A frozen indoor coil is always one of two things: not enough airflow over it, or not enough refrigerant in it. Both are easy to diagnose with proper instruments. Both will keep happening until you fix the actual cause.
Typical price
$59 diagnostic + repair (varies by cause)
Time to fix
60–90 minutes diagnosis (after coil thaws)
Urgency
High — keeps damaging the compressor each time it freezes
Your indoor evaporator coil normally runs around 40°F. That's cold but not freezing. It freezes when something changes: airflow drops (so air spends too long in contact with the coil and gets too cold), or refrigerant drops (so the coil's surface temperature drops below 32°F).
The fix is two steps. First, thaw it — turn the AC off, set the fan to ON, and let it drain for 1–4 hours. Second, find why it froze. Common causes: clogged filter, dirty blower wheel, low refrigerant from a leak, blocked return air, closed supply registers, or a bad blower motor.
Our diagnostic is $59. If you've already thawed it and it froze again, that confirms an underlying problem — and we'll find it the same visit. Skip the 'pour hot water on it' tricks online; that warps the fins.
What it costs in San Antonio
$59 diagnostic + repair (varies by cause) — Most common fixes: filter change (free), refrigerant leak repair ($349+), blower wheel cleaning ($189–$389), refrigerant recharge ($250–$700). Our $59 diagnostic is waived when you approve the repair, so you only pay for the fix itself.
If two or more of these sound familiar, it's probably your frozen ac coil repair.
Here's exactly what a Carnes and Sons tech does at your house — no mystery, no upselling.
We can't diagnose a frozen coil. Coil has to be fully thawed first — usually 1–4 hours with the blower running. We'll wait or schedule the return after you thaw it overnight.
Static pressure measurement, blower amp draw, filter condition, coil visual. Airflow problems cause 60%+ of frozen coils in San Antonio.
Superheat and subcool readings tell us if the charge is right. Low refrigerant means there's a leak — we run electronic leak detection.
Whether it's a filter, a leak, a blower, or a clogged drain — we fix the root cause and run the system long enough to confirm the coil stays clear and the temperature split is right.
Get Your Frozen AC Coil Repair Diagnosed Today
Tell us what's happening. We'll text you back in minutes — no call center, no robo-calls.
Two possible causes: airflow problem (clogged filter, dirty blower, dirty coil, closed vents) or refrigerant problem (leak in the sealed system). Both are diagnosable in one visit with the right instruments. Thawing it without fixing the cause means it'll just freeze again.
Turn the thermostat to OFF, then switch the fan to ON. The blower will move warm air across the coil and melt the ice in 1–4 hours. Don't use a hairdryer or hot water — both can warp the aluminum fins.
Yes. Liquid refrigerant returning to the compressor (called 'slugging') can crack valves and destroy the compressor. Every freeze/thaw cycle adds wear. One freeze is normal; repeated freezes will eventually total the system.
Diagnostic is $59 (waived with repair). The repair price depends on the cause: filter change is free, refrigerant leak repair is $349+, refrigerant recharge is $250–$700, blower wheel cleaning is $189–$389.
No — turn the thermostat off and the fan on to thaw it. Running it frozen damages the compressor and won't cool the house anyway (ice blocks all the airflow).
Same problem — when the indoor coil is too cold (low airflow or low refrigerant), the cold travels all the way back through the suction line to the outdoor unit and ice forms on the line.
Yes — change your filter every 60–90 days (or use a quality pleated MERV 8–11), keep all supply registers open, get an annual tune-up, and never set the thermostat below 70° in winter or on a cool day.
Don't do it. Closing vents increases static pressure, reduces airflow over the coil, and is one of the most common causes of frozen coils in San Antonio. Your AC was sized for the whole house — restricting airflow doesn't save money, it kills the system.
We're based in Stone Oak and roll trucks across San Antonio and the surrounding Hill Country every day.
License TACLB29435E · Family-Owned Since 1996
Cities & neighborhoods we serve
San Antonio · Stone Oak · Alamo Heights · Hollywood Park · Hill Country Village · Shavano Park · Castle Hills · Leon Valley · Helotes · Boerne · Fair Oaks Ranch · Bulverde · Timberwood Park · Garden Ridge · Schertz · Cibolo · Selma · Universal City · Live Oak · Converse · Windcrest · New Braunfels
No call center. The owner or one of his sons picks up.
(210) 600-5091