Water or Ice Around Unit in Kootenai, ID

Understanding why this happens helps you make a smarter decision when we walk you through your options. There are several distinct failure paths that lead to the same symptom.

Restricted Airflow Across the Evaporator Coil

Your evaporator coil works by absorbing heat from the air moving across it. If airflow drops - from a clogged filter, a dirty coil, or a failing blower motor - the coil gets too cold. Refrigerant inside it drops below freezing. Moisture in the air freezes onto the coil surface. Ice builds up, airflow drops further, and the cycle accelerates.

This is the most common cause of a frozen coil, and it's often the result of deferred maintenance. Kootenai County has seen significant growth over the past 15–20 years. A lot of homes built during that building boom are now running builder-grade equipment that's hitting the end of its service life - blower motors wearing out, coils that haven't been cleaned in years, filters that get changed inconsistently.

Low Refrigerant Charge

Refrigerant doesn't get "used up" - it circulates in a closed loop. If the charge is low, there's a leak somewhere in the system. Low refrigerant causes the pressure in the evaporator coil to drop, which drops the temperature, which causes freezing.

The important point: adding refrigerant without finding and fixing the leak is a temporary patch. The charge will drop again. We find the leak first.

Clogged Condensate Drain

Your AC removes humidity from the air as it cools. That moisture collects in a drain pan and exits through a condensate drain line. When that line clogs - algae, debris, and mineral buildup are common culprits - the pan overflows. That's your water on the floor.

This one has nothing to do with refrigerant or airflow. It's a drainage failure. But it can cause real water damage if it's not caught.

Dirty Evaporator Coil

Even with regular filter changes, the evaporator coil accumulates a thin layer of dust and debris over time. That layer acts as insulation, reducing the coil's ability to absorb heat. The coil runs colder than it should, and freezing follows.

Thermostat or Control Issues

Running the AC when outdoor temperatures are too low - below roughly 60°F - can also cause the coil to freeze. If your thermostat is malfunctioning or set incorrectly, the system may run in conditions it wasn't designed for.

Before you call, there are a few safe checks you can do. These won't fix the problem, but they'll give you useful information and may prevent additional damage.

• Turn the system off. If you see ice, switch the thermostat to "off" or "fan only." Running a frozen system harder won't help - it accelerates compressor wear.
• Check your air filter. Pull it out and hold it up to a light. If you can't see light through it, it's overdue for replacement. A clogged filter is a common contributor to freeze-ups.
• Check your supply vents. Walk through the home and make sure all supply and return vents are open and unobstructed. Closed vents reduce airflow and can contribute to coil freezing.
• Look at the drain pan. If it's full of standing water, your condensate drain is likely clogged. Don't try to clear it with a shop vac unless you know where the drain line exits - you can push debris further in.
• Do not add refrigerant yourself. Refrigerant handling requires EPA certification. It's also pointless without knowing the system's charge spec and whether there's a leak.