A frozen AC unit usually has a frozen evaporator coil inside the air handler, furnace cabinet, or indoor unit. Restricted airflow, low refrigerant charge, refrigerant leaks, blower problems, and improper refrigerant flow can lower the coil temperature below freezing. Moisture then freezes onto the coil, blocks airflow, and reduces cooling. A coil that freezes this way typically causes the home to stop cooling properly even while the AC runs — the ice blocks the heat exchange needed to maintain comfort.
Quick Answer: Why Does My AC Keep Freezing?
If you want the short version:
Airflow & filters
A dirty filter, blocked return grille, closed supply registers, or a dirty evaporator coil are the most common — and the ones you can safely check yourself.
Refrigerant & controls
Low refrigerant, refrigerant leaks, a weak blower, metering-device faults, or control issues need licensed HVAC diagnosis — not a DIY fix.
The fastest way to narrow it down is to match the symptom to the likely cause and see what to do first:
| What you notice | Most likely direction | First safe step |
|---|---|---|
| Frost or ice around the indoor unit | Frozen evaporator coil | Thaw, then DIY |
| Weak airflow from several vents | Filter, blower, coil, or duct restriction | DIY first |
| Ice on the large insulated copper line | Airflow or refrigerant-side issue | Thaw, then pro |
| Water under the air handler after shutdown | Thawing ice and excess meltwater | Protect area |
| Filter is clean but the AC keeps freezing | Blower, dirty coil, refrigerant, or control issue | Pro |
A frozen coil is not a final diagnosis. It is the result of a heat-transfer problem — and the right repair depends on what caused the coil to freeze.
What to Do When Your AC Unit Freezes Up Inside
Turn cooling off, allow the coil to thaw, and correct visible airflow restrictions before restarting the system.
This is the correct first response when you have a frozen AC unit inside, an AC unit iced over, or visible ice around the indoor air handler. Running cooling while the coil is frozen adds more ice, further blocks airflow, and can create a large amount of water when the system finally thaws.
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1
Turn Cooling Off
Set the thermostat from Cool to Off. This stops the refrigerant cycle from continuing to lower coil temperature. If the unit has already shut off completely and won't restart, see our guide on why your AC won't turn on.
Do not leave the AC running because the home feels warm. A frozen coil cannot absorb heat normally. Keeping the system on can cause more ice buildup, weaker airflow, and more thaw water later.
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2
Let the Coil Thaw Fully
Allow the frozen evaporator coil to thaw naturally. A light frost layer may melt in a few hours. A fully iced-up evaporator coil can take longer, especially when ice covers the coil fins and refrigerant lines.
Do not:- Chip or scrape ice from coil fins.
- Use a heat gun or direct flame.
- Pour hot water into the air handler.
- Pry open sealed equipment panels.
- Bend coil fins.
- Spray household chemicals into the coil compartment.
The evaporator coil contains delicate aluminum fins and refrigerant tubing. Physical damage can turn a freezing problem into a refrigerant leak or coil replacement issue.
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3
Use Fan-Only Mode Carefully
Fan-only mode can help thaw a frozen AC coil by moving room-temperature air across it. Use this setting only when the indoor blower operates normally and water is not near electrical components.
Leave the fan off when:- The blower is not moving air.
- The air handler makes unusual motor or electrical noises.
- Water is near wiring or control boards.
- Water is leaking from the cabinet into a sensitive area.
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4
Replace a Dirty Air Filter
A dirty filter is one of the few common causes that homeowners can safely correct. Replace the filter when it is dark, clogged, collapsed, wet, incorrectly sized, or installed backward.
A clean filter does not prove the system has enough airflow. It only removes one possible restriction. The AC unit keeps freezing up after a filter change when another problem remains, such as a dirty indoor coil, weak blower, duct restriction, refrigerant issue, or control fault.
Replace the filter before restarting the AC. Schedule a seasonal AC maintenance inspection if the evaporator coil freezes again after the filter change.
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5
Clear Accessible Airflow Restrictions
Check visible air paths without dismantling the system:
- Move furniture away from return grilles.
- Remove storage boxes from around filter grilles.
- Open accessible supply registers that have been closed.
- Lift rugs or curtains that block returns.
- Make sure the new filter fits correctly and the filter door closes properly.
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6
Manage Thaw Water
A frozen coil can release a large amount of water as ice melts. Protect flooring with towels or a wet/dry vacuum where safe. Watch the area around the indoor air handler, attic access, closet unit, secondary drain pan, and ceiling below attic equipment.
Thawing solves the immediate ice problem — it does not identify why the coil froze. Frost that returns after a full thaw points to an active airflow, refrigerant, blower, or control issue.
How to Unfreeze an AC Unit Safely
The safest way to unfreeze an AC unit is to turn cooling off, allow the ice to thaw, replace a dirty filter, and clear accessible airflow restrictions.
That sequence is the practical answer to "how to unfreeze AC unit." It is not a complete repair plan. Restart cooling only after visible ice is gone and basic airflow checks are complete. If the system is a candidate for full replacement rather than repair, our team can walk you through a permitted AC installation sized correctly for your home's load.
Is There a Quick Fix for AC Freezing Up?
A quick fix exists only when the cause is an obvious airflow restriction — such as a severely clogged filter or a blocked return grille. Repeated freezing is not a quick-fix problem.
A quick thaw is not a permanent frozen evaporator coil fix. Repeated freezing requires diagnosis because the cause may involve the blower, coil cleanliness, refrigerant charge, refrigerant leak, expansion valve, duct system, or controls. A licensed AC repair visit identifies the specific fault before any work begins. When recurring freeze-ups point to an aging system, a full AC system replacement with a correctly sized unit often costs less long-term than continued repairs.
How to Tell If AC Is Frozen
A frozen AC often shows frost, ice, weak airflow, warm supply air, long cooling cycles, or water around the indoor unit after shutdown.
The evaporator coil may be hidden inside the air handler, so visible ice is not the only clue. These are the most useful signs of frozen AC coils:
- Frost around the indoor coil cabinet.
- Ice buildup on the evaporator coil or refrigerant tubing.
- A frozen suction line, usually the larger insulated copper line.
- Weak airflow from multiple supply vents.
- Warm or less-cool air while the AC runs.
- Longer run times without reaching the thermostat setpoint.
- Water under the indoor unit after the system stops.
- A wet filter compartment.
- A drain pan filling quickly during thawing.
- Frost returning after you replace the filter.
- Ice on an AC coil that was not present earlier in the day.
Frost vs an Iced-Over Coil
Frost is often the early stage of a freeze-up, while solid ice can block airflow through the coil almost completely.
A small frost layer means the coil is operating too cold. An iced-over evaporator coil means the freeze-up has progressed far enough to restrict airflow and cooling capacity.
As the ice grows, it blocks the narrow spaces between coil fins. That reduces airflow, which makes the coil even colder. The system then enters a cycle where the AC freezes up more severely with continued operation.
What a Frozen AC Unit Actually Means
A frozen AC unit usually means the indoor evaporator coil is frozen, not that the entire air-conditioning system or outdoor condenser has failed.
Homeowners use several natural phrases for the same visible condition:
- Air conditioner freezing
- HVAC frozen
- Home AC freezing up
- AC freezes up
- AC coils freeze up
- AC unit iced over
- Frozen AC unit
- Frozen AC unit inside
Those phrases are useful because they describe what the homeowner sees. The technical diagnosis starts by identifying the exact component.
Frozen Evaporator Coil vs Condenser Freezing Up
A frozen evaporator coil is the common cooling-mode problem; a condenser freezing up is usually a different issue or a homeowner description of ice seen on refrigerant tubing.
The evaporator coil sits indoors and absorbs heat from household air. The condenser coil sits outdoors and releases heat. In normal cooling mode, the indoor evaporator coil is the coil most likely to freeze.
When someone says the condenser is freezing up, the visible ice may actually be on the suction line leading to the outdoor unit. The suction line is a symptom location, not automatically the root cause.
Is Compressor Freezing Up the Same Problem?
"Compressor freezing up" usually describes ice near refrigerant lines or the outdoor unit, not ice inside the compressor itself.
The compressor moves refrigerant through the system. A badly frozen coil can reduce system performance and place extra strain on refrigeration components. Do not keep operating the system when ice repeatedly reaches the refrigerant line or outdoor unit.
Evaporator Coil Frozen vs AC Evaporator Coil Frozen
An evaporator coil frozen condition and an AC evaporator coil frozen condition refer to the same core issue: the indoor cooling coil has become cold enough to freeze moisture from the air.
The key question is not only whether the coil is frozen. The key question is why the coil temperature dropped below freezing.
What Causes AC to Freeze Up?
AC coils freeze up when airflow is too low, refrigerant conditions are abnormal, refrigerant flow is restricted, or operating controls allow the evaporator coil to run too cold.
The causes below follow a diagnostic order. Airflow comes first because it is common and often visible. Refrigerant and metering issues come next because they require professional measurement and repair.
1. Dirty or Restrictive Air Filter
A dirty air filter can make an air conditioner freeze because it restricts the warm indoor air that should move across the evaporator coil.
The filter can create trouble when it is packed with dust, installed backward, bent inward, wet, incorrectly sized, or too restrictive for the equipment.
A filter restriction becomes more serious when it combines with another issue, such as a dirty coil, blocked return, weak blower, or duct problem.
Check for:
- Dark or gray filter media.
- Dust packed across the surface.
- A filter that bows inward.
- A filter that does not fit the slot.
- A filter arrow facing the wrong direction.
- Lint or debris around the return grille.
- A wet filter caused by thaw water.
Replace the filter before restarting the AC. Book service if the evaporator coil freezes again.
2. Blocked Return Airflow
A blocked return vent reduces the warm air entering the air handler and can make the evaporator coil freeze.
Return airflow carries household air back to the system for cooling. When that path is restricted, the coil absorbs less heat. Lower heat absorption allows coil temperature to fall.
Return-air restrictions include furniture covering a return grille, storage blocking the filter grille, a closed return, collapsed flex duct, insulation debris near the intake, a damaged return duct, or a disconnected return connection.
Check accessible grilles only. Move furniture, storage, curtains, and rugs away from returns. Do not dismantle ductwork as a DIY repair.
3. Closed Registers or Duct Restrictions
Closed supply registers and duct restrictions can contribute to AC freeze-up when they reduce overall system airflow.
One partly closed register rarely causes a frozen coil on its own. The issue becomes more likely when several registers are closed, dampers are incorrectly adjusted, ducts are crushed, flex duct has collapsed, or the system already has restricted airflow from a dirty filter or coil.
Duct-related symptoms include:
- Weak airflow in several rooms.
- Rooms that overcool while other rooms stay warm.
- Whistling at registers.
- Long cooling cycles.
- A clean filter but recurring frost.
- Poor room-to-room balance.
A technician can test airflow and inspect ducts without guessing based on one vent.
4. Dirty Evaporator Coil
A dirty evaporator coil can make AC coils freeze up because dirt insulates the coil surface and restricts the air passages between the fins.
The coil must transfer heat from indoor air into the refrigerant. Dust, pet hair, kitchen particles, biological buildup, and filter bypass reduce that transfer.
A dirty coil often creates a different pattern from a dirty filter. The filter may look clean, but the system still has weak airflow, poor humidity control, long run times, or repeat freeze-ups.
Signs that suggest a dirty coil include:
- Weak airflow after replacing the filter.
- Reduced cooling capacity.
- Longer cooling cycles.
- Excess indoor humidity.
- Frost on the indoor coil.
- Ice that returns after thawing.
- Dust buildup inside the air handler.
A clean filter does not guarantee a clean coil. Poor filter fit, gaps around the filter rack, return-side duct leakage, and long maintenance gaps can allow dust to build on evaporator fins.
5. Blower Motor, Blower Wheel, or Fan-Speed Problem
A blower problem can freeze an AC coil by moving too little warm air across the evaporator.
The blower can run while still delivering inadequate airflow. A weak motor, dirty blower wheel, incorrect fan speed, failing capacitor, relay issue, or control fault can all reduce air volume.
Possible blower-related symptoms include:
- Weak airflow throughout the home.
- Airflow that stays weak after filter replacement.
- A blower that starts slowly.
- A blower that runs inconsistently.
- Unusual motor noise.
- Warm air from vents while the outdoor unit runs.
- A frozen coil despite open registers and a clean filter.
A blower issue requires electrical and airflow diagnosis. It is not something to solve by repeatedly resetting the thermostat.
6. Low Refrigerant Charge
Low refrigerant charge can make the evaporator coil freeze by lowering refrigerant pressure and coil saturation temperature.
When refrigerant charge is low, the coil can become colder than intended. Moisture then freezes onto the coil instead of draining as normal condensate.
Possible symptoms include:
- Frost on the suction line.
- An AC evaporator coil frozen after filter replacement.
- Warm or weak cooling.
- Long run times.
- Poor humidity removal.
- Hissing near refrigerant tubing.
- Ice returning after the system thaws.
Low refrigerant charge is not a homeowner maintenance issue. Do not add refrigerant based on frost alone. The system needs professional evaluation because a leak, prior charging error, metering issue, or another refrigeration fault may be involved.
7. Refrigerant Leak
A refrigerant leak can cause an AC unit to keep freezing up because the system gradually loses charge and the evaporator coil operates too cold.
A small leak can cause gradual changes rather than an immediate shutdown. Cooling may become weaker, the system may run longer, frost may appear occasionally, and the same coil may freeze repeatedly.
A frozen evaporator coil does not prove a refrigerant leak. Airflow problems can create the same symptom. The technician must separate the two causes through proper diagnosis.
A professional refrigerant repair involves:
- Confirming whether a leak exists.
- Identifying the likely leak area.
- Repairing the defect where practical.
- Testing the repair.
- Restoring charge according to manufacturer procedures.
- Confirming stable cooling performance afterward.
Adding refrigerant without investigating why charge is low can leave the original fault active.
8. Metering Device or Refrigerant-Flow Fault
A metering-device fault can cause an evaporator coil frozen condition by restricting or mismanaging refrigerant flow into the indoor coil.
The metering device may be a TXV, expansion valve, fixed orifice, or piston. It controls how refrigerant enters the evaporator coil. A restricted or malfunctioning component can starve the coil and create freeze-up conditions.
This is technician-only work. Diagnosis can involve pressure readings, superheat, subcooling, coil temperature, refrigerant charge, and manufacturer-specific operating procedures.
Do not adjust, bypass, or replace refrigerant metering parts without qualified HVAC service.
9. Cool Outdoor Temperatures or Control Issues
Air conditioner freezing can occur during cool outdoor weather when the system runs without the controls needed for low-ambient cooling.
This pattern may appear at night, during mild weather, in spring or fall, or when the system has special cooling loads. Cool outdoor conditions usually do not explain every freeze-up, but they can worsen a system that already has marginal airflow or refrigerant performance.
Control-related contributors can include:
- Incorrect thermostat sensing.
- A continuous cooling call.
- Faulty coil-temperature sensor.
- Ductless mini-split freeze-protection issue.
- Control-board fault.
- Incorrect blower command.
- Low-ambient control issue.
A heat pump defrost cycle belongs to heating operation, where the outdoor coil may frost. It is not the normal fix for a frozen indoor coil while the system is cooling.
Why Does My AC Keep Freezing After It Thaws?
Your AC keeps freezing after thawing because the ice melted but the cause of the freeze-up remained active.
A thawed coil can look normal for a short time. Once cooling restarts, the same airflow restriction or refrigerant condition can pull coil temperature down again.
Repeated freeze-ups commonly point to:
- A clean-looking filter but dirty evaporator coil.
- A weak blower or dirty blower wheel.
- Blocked return airflow.
- Duct restriction or closed registers.
- Low refrigerant charge.
- Refrigerant leak.
- Metering-device issue.
- Cool-weather cooling conditions.
- Thermostat or sensor fault.
The recurrence pattern matters. An AC that freezes only after long runtime may have a different cause from an AC that frosts within minutes of starting.
Why a Frozen AC Coil Can Leak Water
A frozen coil can leak water after thawing because melting ice creates more water than the condensate system can remove quickly.
The condensate drain system may not have caused the original freeze-up. It often handles the aftermath. A large amount of meltwater can expose a clogged drain line, cracked drain pan, failed condensate pump, loose fitting, poor slope, or overflow safety issue.
Watch for:
- Water under the air handler.
- A full or overflowing drain pan.
- Water around a condensate pump.
- Ceiling staining below attic equipment.
- A wet filter compartment.
- Water near a PVC drain pipe.
- Musty odors after repeated moisture exposure.
DIY vs Pro: What You Can Check and What Needs HVAC Service
Homeowners can check accessible airflow restrictions and visible symptoms, but repeated freeze-ups, refrigerant concerns, blower faults, electrical moisture, and metering problems need professional diagnosis.
| Situation | Safe homeowner action | Who fixes it |
|---|---|---|
| Dirty filter | Replace with correct size and direction | DIY first |
| Blocked return grille | Clear furniture or storage | DIY first |
| Closed registers | Open accessible registers | DIY first |
| Visible ice | Turn cooling off and allow thawing | Thaw, then pro |
| Water near air handler | Remove standing water safely | Pro |
| Frozen suction line | Stop cooling and document the symptom | Pro |
| Wet ceiling | Turn system off and protect the area | Pro |
| Suspected refrigerant issue | Observe symptoms only | Pro |
| Blower not moving air | Turn the system off | Pro |
| AC unit keeps freezing up | Record the timing and symptoms | Pro |
Safe Homeowner Checks
- Replace a visibly dirty HVAC filter.
- Confirm the filter size and airflow direction.
- Clear blocked return grilles.
- Open accessible supply registers.
- Turn cooling off when frost or ice appears.
- Allow the coil to thaw naturally.
- Remove visible meltwater safely.
- Observe whether the drain outlet begins dripping during thawing.
- Take photos of ice, water, filter condition, and refrigerant tubing.
- Note whether freezing happens during the day, at night, after filter replacement, or during cool weather.
Technician-Only Work
- Refrigerant leak detection.
- Refrigerant recovery and charging.
- Metering-device diagnosis.
- Blower motor testing.
- Blower capacitor or control testing.
- Evaporator-coil cleaning inside sealed equipment.
- Static-pressure testing.
- Duct restriction diagnosis.
- Thermostat and control-board diagnosis.
- Condensate pump repair.
- Drain-pan replacement.
- Repeated frozen evaporator coil repair.
How HVAC Technicians Diagnose a Frozen Evaporator Coil
An HVAC technician diagnoses a frozen AC coil by separating airflow problems from refrigerant, component, and control faults.
The system usually needs to thaw enough for the coil and airflow path to be inspected properly. A complete diagnostic visit may include:
- Inspecting the filter and return-air path.
- Checking coil cleanliness and frost pattern.
- Evaluating blower motor, wheel, speed, and controls.
- Reviewing supply and return airflow.
- Inspecting ducts for restrictions.
- Checking the condensate pan, drain line, trap, and pump for thaw-water problems.
- Measuring cooling-system operation.
- Testing for refrigerant leak symptoms.
- Evaluating metering-device behavior where appropriate.
- Reviewing thermostat, sensors, and control-board operation.
- Confirming stable operation after repair.
The best frozen evaporator coil fix depends on the cause. Replacing a filter fixes only a filter restriction. Cleaning a dirty coil fixes only coil contamination. Adding refrigerant without finding the reason for low charge can leave the original problem active.
Frozen AC Coil Differences by System Type
Central AC, ductless mini-splits, window units, and portable ACs can all freeze, but the equipment layout and homeowner-safe checks differ.
Central AC
A central system usually includes an indoor air handler or furnace cabinet, evaporator coil, blower, return ductwork, supply ducts, drain pan, drain line, refrigerant lines, and outdoor condensing unit.
For central AC, start with the filter, return airflow, blower, indoor coil, refrigerant symptoms, and drainage aftermath.
Ductless Mini-Split
A mini-split can freeze when indoor filters are dirty, the indoor coil is contaminated, the fan wheel is restricted, refrigerant performance is abnormal, or a sensor issue affects freeze protection.
Homeowner checks should stay limited to filters, visible ice, louver position, and drainage. Coil cleaning, fan-wheel cleaning, refrigerant work, and sensor diagnosis require service.
Window AC
A window AC can freeze because of dirty filters, dirty coils, low airflow, cool-weather operation, or refrigerant faults. The system is self-contained, so drainage and component access differ from central AC equipment.
Portable AC
A portable AC can freeze at the evaporator when airflow is restricted, filters are dirty, room conditions are unusual, or controls and refrigerant performance are abnormal. Follow the manufacturer's instructions for tank drainage and hose setup.
How to Prevent Home AC Freezing Up Again
Preventing home AC freezing up requires stable airflow, clean coil surfaces, open air paths, healthy refrigerant operation, and suitable cooling conditions.
Use these targeted prevention steps:
- Replace filters before they become heavily loaded.
- Use the correct filter size and type.
- Keep return grilles clear of furniture, storage, rugs, and dust.
- Avoid closing multiple supply registers.
- Address weak airflow before frost appears.
- Schedule coil cleaning when airflow stays weak with a clean filter.
- Inspect ducts when some rooms have poor airflow.
- Repair repeated drain issues so thaw water does not cause property damage.
- Avoid unnecessary cooling during unusually cool outdoor weather unless the system supports low-ambient operation.
- Schedule HVAC maintenance when the system has long run times, uneven cooling, repeat frost, or reduced humidity control.
When to Call an HVAC Technician for a Frozen AC Unit
Call an HVAC technician when the coil freezes again after thawing, the filter is clean, cooling is weak, water leaks inside, or refrigerant or blower issues are possible.
Schedule service when you notice:
- A frozen evaporator coil more than once.
- An evaporator coil frozen after filter replacement.
- A frozen suction line that returns after thawing.
- Weak airflow throughout the home.
- Warm air from supply vents.
- Water under the indoor unit.
- A full drain pan.
- Water leaking through the ceiling.
- A blower that runs weakly or does not run.
- Frost after a filter replacement.
- Hissing near refrigerant lines.
- Long cooling cycles with poor comfort.
- A clean filter but recurring ice buildup.
- An AC unit iced over during normal hot-weather cooling.
- A suspected refrigerant leak, metering fault, or control issue.
Frequently Asked Questions
Why is my AC freezing up?
Your AC is freezing up because the evaporator coil is operating too cold for the amount of heat and airflow reaching it. Restricted airflow, low refrigerant charge, refrigerant leaks, dirty coils, blower issues, and controls can all create that condition.
What causes AC to freeze up?
Low airflow and refrigerant-side faults are the most common causes of AC freeze-up. Dirty filters, blocked returns, dirty evaporator coils, weak blowers, low refrigerant charge, leaks, and metering faults reduce normal heat transfer across the coil.
What should I do when my AC unit freezes up inside?
Turn cooling off, allow the coil to thaw, replace a dirty filter, clear accessible airflow restrictions, and protect the area from meltwater. Arrange service when frost returns, cooling stays weak, or water leaks indoors.
How do I unfreeze an AC unit safely?
Turn cooling off and let the coil thaw naturally. Fan-only mode can help when airflow is normal and water is not near electrical parts. Do not chip ice, use direct heat, or add refrigerant yourself.
How can I tell if my AC is frozen?
Look for frost, ice, weak airflow, warm supply air, water after shutdown, a frozen suction line, or long cooling cycles. The coil may be hidden inside the air handler, so performance symptoms matter too.
Why is my AC unit frozen but the outdoor unit still runs?
The outdoor unit can keep running while the indoor coil is frozen because the thermostat is still calling for cooling. The indoor coil may be blocked by ice, airflow may be too low, or refrigerant conditions may be abnormal.
Why is my condenser freezing up?
What looks like condenser freezing up often starts with ice on the suction line or a frozen indoor evaporator coil. The indoor evaporator and outdoor condenser perform different jobs, so the technician needs to identify where the freeze-up began.
Why is my compressor freezing up?
Ice near the compressor usually indicates a frozen refrigerant line or evaporator-side problem, not ice inside the compressor itself. Turn cooling off and request service when the condition repeats.
Can I defrost AC coils and keep using the system?
You can allow AC coils to thaw, but defrosting the coil does not fix the root cause. Restart only after the ice is gone and accessible airflow restrictions are corrected. Stop again and schedule service if frost returns.
Is a frozen evaporator coil fix expensive?
A frozen evaporator coil fix depends on the cause. A dirty filter is simple, while coil cleaning, blower repair, refrigerant leak detection, metering-device work, or control diagnosis requires more labor and equipment.
Why does my AC leak water after it freezes?
A frozen coil leaks water when thawing ice creates more meltwater than the drain pan and condensate system can remove. Drain clogs, cracked pans, pump failure, and poor drain slope can worsen the leak.
Final Takeaway
An AC freezes when the evaporator coil becomes too cold because airflow, refrigerant conditions, refrigerant flow, or controls are not keeping it within normal operating range.
Stop cooling, let the coil thaw, replace a dirty filter, clear accessible returns, and protect the area from meltwater. Then judge what happens after restart. A system that freezes again needs diagnosis — not another temporary thaw.