Why Is My AC Suction Line Frozen

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If you find yourself suffering from the summer heat even though your air conditioner is on full blast, this is a sure sign your AC isn’t working properly. One of the easiest ways to spot an AC issue is to check your outside unit suction line. If your line is coated in ice despite rising summer temperatures, this means your AC needs attention from your Denver HVAC experts at Bell Plumbing, Heating, Cooling & Electrical. Here’s why your AC suction line is frozen, and what you can do about it.   

Clogged Air Filters

The first step to troubleshooting a frozen suction line is to check your air filter. You should be changing your AC air filters monthly in peak season. If not, they become clogged and prevent proper airflow. In turn, it freezes the coils. Check your filters and if they appear clogged, try replacing them to see if this helps.

Closed Supply Vents

If your AC seems to be hitting rooms that are too cold, you might close the vents to try to redirect the air to warmer rooms. However, this can actually lead to issues because it too can limit airflow. Go through your home and open any supply vents that are closed to see if this helps.

Blocked Return Vents

Return vents are designed to suck air into the unit as part of the airflow process. If they are blocked it can cause issues with the unit. You should keep return vents clean. If your AC suction line is frozen, check your return vents and clean any that are blocked.

Fan or Blower Not Working

Your blowers and fans work together to pull warm air from rooms into the system and then force cool air out. If they aren’t working, nothing really works. There isn’t adequate flow, so your line can freeze. Listen for your fan and blower to see if it is working. If you either don’t hear anything, or it sounds like it is struggling you’ll need to call Bell Plumbing, Heating, Cooling & Electrical for repairs.

Leaking Refrigerant and Dirty Evaporator Coils

If you do all of these checks and fixes and nothing works, it’s time to call for professional help to check and see if you have something else causing the freezing line such as low refrigerant levels. This is typically caused by a leak in the system. There will be other notable issues if your refrigerant is leaking including increased energy bills, blowing warm air instead of cold, and hissing sounds. We will check the refrigerant, find the leak, and repair it. We’ll also replace the refrigerant so your AC will be back to proper cooling function. 

Another potential issue is a dirty evaporator coil. Like your air filters, these coils can’t work properly when they are dirty. That’s why regular maintenance for your AC is so important. Your maintenance call includes a good cleaning of your evaporator coil. Our AC expert will also check the coils to see if they could be causing the issue.

Can I Just Thaw My AC Line?

This is often a DIYer solution when they spot a frozen suction line. Although you can turn off your thermostat and leave the fan on for a few hours, it will thaw the line, but won’t address the actual problem. This will lead to an endless cycle of you thawing out the line and then having a few hours of cool air and then thawing it out again when it refreezes. As well, when the line thaws it produces water which can lead to water damage to your house. It’s always best to call Bell Plumbing and Heating to come and assess the problem. We’ll figure out what’s wrong and make the necessary repairs that will get your AC back in tip-top condition.

Regular Maintenance

The best way to avoid frozen suction lines is to replace your air filters and schedule regular AC maintenance. A service call once a year will ensure your coils are clean, your filters aren’t clogged, and all the components of your AC are in working order. You’ll save wear and tear on your system, while also keeping your system running more efficiently. This will show up on your energy bills. Best of all your family will be comfortable even on the hottest day of the year.

While it can be tempting to take the DIY route, you can actually cause more damage than good. A properly maintained AC unit will reduce energy costs and keep you comfortable all summer long. 

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