If your AC suddenly stops blowing cold air and you spot ice on the lines around the unit, you’re likely dealing with one of the most frustrating HVAC issues out there: a frozen system.
Now, you may wonder, “Why would my HVAC system freeze during the summer?” Shouldn’t the opposite happen if something is wrong? No, and this is actually a common misconception among homeowners.
In this blog post, you’ll learn what to do when your HVAC freezes up in summer and when it’s time to contact SM Mechanical Services LLC for the best HVAC services in Newington, CT.
Why AC Systems Freeze Up in the Middle of Summer in Newington, CT
Before you decide what to do when your HVAC freezes up in summer, it helps to understand the core science behind what’s causing it.
- A frozen evaporator coil forms when the coil drops below 32°F and freezes moisture from the air around it.
- Restricted airflow prevents warm air from reaching the coil, which causes the coil’s surface temperature to fall below freezing.
- Furniture, dirty filters, or closed vents reduce airflow and stop the coil from absorbing enough heat.
- Low refrigerant levels drop internal pressure, which makes the refrigerant expand too much and overcool the coil.
- A frozen coil blocks heat exchange entirely, which stops your system from cooling your home.
Understanding these causes helps you troubleshoot quickly and prevent a full system replacement.
Steps To Take To Fix a Frozen AC in Summer
If you think your HVAC system has frozen, start by turning off the system and letting the ice melt. The next sections walk you through in more detail what to do when your HVAC freezes up in summer.
Check and Replace the Air Filter
A dirty air filter blocks airflow and causes the evaporator coil to freeze.
Pull out your current filter and hold it up to the light. If light doesn’t pass through, the filter blocks airflow and needs to be replaced. Replace it with a clean filter rated for your system’s airflow. During summer, make sure you change filters every month, especially if you run your AC daily. A clean filter helps air move freely through the system and lets the coil absorb heat.
Once you replace the filter, move on to checking airflow throughout your home.
Open All Vents and Clear Return Grilles
Blocked vents and returns create restricted airflow that traps cold air inside your system, leading to freezing. Walk through each room and make sure every vent isn’t covered by rugs, furniture, or curtains.
Avoid closing vents in unused rooms, even if you are trying to save energy. Closed or blocked ducts raise static pressure and reduce airflow across the evaporator coil. Look closely for large furniture sitting over return grilles without you noticing.
After restoring airflow, check the thermostat settings to make sure the system is not overcooling.
Adjust Thermostat Settings To Prevent Overcooling
Bad thermostat settings run your AC longer than necessary and drop internal temperatures too low. Set your system to “auto” so the fan only runs when cooling is active.
Do not set the thermostat below 70°F during hot weather, even if your home feels warm. If the display shows a temperature that does not match the actual room temperature, the sensor could be faulty. Look for stuck relays or signs of short cycling that make the system run constantly.
Clear Out the Condensate Drain Line
A condensate drain blockage stops water from draining, which causes nearby parts to freeze.
Look under your indoor unit for standing water or overflow around the drain pan. Use a shop vac on the outdoor access point to pull out any debris. Pour a mixture of vinegar and water into the drain to clear out mold or algae. If water keeps backing up, a break or clog in the line blocks the flow.
Call a Technician in Newington, CT, To Check Refrigerant Levels
Low refrigerant levels usually mean there’s a leak. Recharging without fixing it won’t stop the freezing. Only licensed techs can check pressure and safely handle repairs. If your AC still freezes after fixing airflow and drainage, contact SM Mechanical Services LLC for expert service in Newington, CT.
Contact SM Mechanical Services LLC To Fix Your Frozen AC
Still wondering what to do when your HVAC freezes up in summer? Contact SM Mechanical Services LLC for expert inspections, coil cleanings, drain clearings, and refrigerant testing in Newington, CT. We’ll fix the issue fast, explain the cause, and help you avoid the dangers of DIY HVAC replacement.