When the AC coil freezes in Garland, TX, ice has built up on the evaporator coil or refrigerant lines and heat can no longer be moved. Restricted airflow and low refrigerant account for most cases. Switch cooling off, wait for the ice to melt and check the basics below first. For a diagnosis, use Call Now and you will be connected with an independent HVAC contractor serving 9 ZIP codes around Garland.
What to do right now
- Switch the thermostat from cool to off and set the fan to on so warm indoor air melts the ice
- Give it several hours. A heavy coil can take most of a day to thaw, so do not chip the ice
- Place towels or a pan under the air handler, because melting ice makes a lot of water
- Replace the filter if it is dirty and open all supply and return registers
- Do not restart cooling until the ice is gone
Why a coil freezes
| Cause | How it freezes the coil | Who fixes it |
|---|---|---|
| Failing blower motor or capacitor | The fan moves too little air | Technician |
| Dirty filter or blocked return | Low airflow lets the coil get too cold | You, or a technician |
| Closed or blocked supply registers | Airflow drops and pressure rises | You |
| Dirty evaporator coil | Dust blocks airflow through the fins | Technician |
| Low refrigerant | Pressure falls and the coil temperature drops below freezing | Technician, with a leak repair |
| Cooling in cool weather | Low outdoor temperatures can freeze a coil | Switch to off and use heat or fan |
What a frozen coil can damage
When ice melts, water can overflow the drain pan and stain ceilings, insulation and floors. If liquid refrigerant reaches the compressor because the coil is frozen, the compressor can be damaged. Ice on the lines outside, or a compressor that is cold and sweating, is a sign to stop the system and call.
Prevent it from coming back
- Do not set the thermostat far below the room temperature on mild days
- Fix refrigerant leaks instead of topping up
- Keep supply and return registers open and clear
- Change the filter on schedule and use the right size
- Have the coil cleaned and the blower tested during a tune-up
What the technician will check
- Refrigerant pressures, superheat and subcooling, and a leak search
- Filter, registers and ductwork for restrictions
- Temperature drop across the coil and static pressure
- Condition of the evaporator coil and the drain
- Blower motor, capacitor and fan speed
Myths and facts
- Myth: a bigger AC is always better. Fact: oversizing causes short cycling and humidity problems.
- Myth: closing vents saves energy. Fact: it raises duct pressure and can cause leaks and noise.
- Myth: set the thermostat very low to cool faster. Fact: the AC cools at a steady rate and just runs longer.
- Myth: maintenance is optional. Fact: dirty coils and weak capacitors cause many summer failures.
- Myth: refrigerant is used up. Fact: low refrigerant means a leak.
HVAC terms explained
- Superheat and subcooling: readings that show whether the refrigerant charge is correct
- Condensate drain: the line that carries moisture out of the house
- Contactor: the switch that sends power to the outdoor unit
- Condenser coil: the outdoor coil where heat is released
- EPA Section 608: the certification required to handle refrigerants
- Capacitor: stores charge to start and run the compressor and fan motors
- Static pressure: a measure of airflow resistance in the ducts
- Evaporator coil: the indoor coil where refrigerant absorbs heat from the air
A checklist for this week
- Write down any noises or smells
- Clear the outdoor unit of debris
- Inspect the drain line outlet and the area around the air handler for water
- Replace the filter and note the date
- Book a tune-up if it has been more than a year
- Test the thermostat and schedule
Ducts, airflow and comfort
Comfort depends on airflow as much as on cooling capacity. Leaky ducts, undersized returns and blocked registers cause hot rooms even when the system is sound. A technician who measures static pressure and airflow, not just refrigerant pressures, will find these problems.
What shapes the written scope
Two AC calls that sound alike can be very different jobs. The written scope should say what the technician found and which of these factors applied.
Have the provider show the diagnostic and the repair as separate items, and list any parts, labor or follow-up that are left out.
- Access to the air handler in the attic or closet and to the outdoor unit
- Whether the fault is an electrical part, an airflow problem, a refrigerant leak or a drainage problem
- Whether the ductwork, return air or thermostat contributes to the problem
- The age, tonnage and refrigerant type of the system
- Warranty status of the parts and whether the equipment is registered with the manufacturer
Safety and rules to know
Three hazards share one machine in an air conditioner: high-voltage electricity, pressurized refrigerant and moving parts. Opening electrical panels, bridging contactors and adding refrigerant are not jobs for homeowners, and capacitors can keep a charge after the power is off.
Certification under EPA Section 608 is required in the United States for anyone buying or handling refrigerant, which must be recovered instead of vented. Request the technician's certification and confirm the contractor's licence through Texas Department of Licensing and Regulation (A/C contractor license).
When to call a professional
Pick up the phone if the system will not start, if ice or water shows up, if the same problem comes back after your own checks, if you hear grinding or banging, or if anyone at home is vulnerable to heat or cold. Call Now at the top of the page puts you through once you describe what the system is doing: an independent HVAC contractor covering your ZIP code confirms the address and diagnoses the system in person.
What this means for a home in Garland
Dallas County suburb of roughly 250,000 east of Dallas, next to Lake Ray Hubbard and Rowlett. Summers regularly reach the upper 90s and 100s, so AC runs almost continuously from June to September.
Housing from the 1960s to the 1980s often has attic ductwork and older systems, including R-22 era equipment. Clay soil can shift and tilt condenser pads. Use these local details when you compare advice, and ask any technician how they apply to your system and your house.
Getting help in Garland and nearby cities
Air Conditioning Repair Garland connects you with independent HVAC contractors covering 9 ZIP codes in Garland, Texas: 75040, 75041, 75042, 75043, 75044, 75045, 75046, 75047, 75049. Requests also reach providers serving Rowlett, Sachse, Richardson, Plano and Wylie. Coverage is confirmed address by address.
Use Call Now at the top of the page and describe what you found. The contractor confirms your address, inspects the system and puts the scope in writing.
Keep reading
Related pages for Garland homeowners: What Size AC Do You Need? Tonnage and Load Calculation; AC Not Cooling? 12 Causes and Fixes; SEER2 Explained for Garland Homeowners; AC Repair or Replace? A Decision Guide for Garland. For the area list, see the service areas page.
Common questions about frozen AC coil: why it happens and what to do
Why is there ice on my AC?
Expect restricted airflow or low refrigerant behind ice, with a dirty filter, blocked registers, a weak blower or a leak as likely sources.
Can I use a hair dryer to melt the ice?
It is safer to turn cooling off, run the fan and let it melt. Heat tools can damage the coil or lines.
Can I keep the AC running with ice on it?
No, because a frozen system that keeps running risks harm to the compressor and water damage.
Is a frozen coil an emergency?
Deal with it quickly, though it only becomes an emergency if water damage is a risk or someone vulnerable lives in the house.
How long does the ice take to melt?
Several hours up to a day depending on the buildup.
Will a new filter fix it?
It will if a dirty filter was the cause. If ice returns, call a technician.