Water or Ice Around Unit in Millwood, WA

Water and ice problems almost always trace back to one of four root causes. Understanding the mechanics helps you know why a real diagnosis matters.

1. Restricted Airflow Across the Evaporator Coil

The evaporator coil works by absorbing heat from the air passing over it. When airflow drops dirty filter, blocked return, collapsed duct the coil gets too cold. Refrigerant inside it drops below freezing. Moisture in the air freezes on contact with the coil surface.

Once ice builds up, it acts as insulation, blocking even more airflow. The cycle accelerates. Eventually the coil is a solid block of ice, and when the system shuts off, all that ice melts straight into the drip pan and potentially over the edge.

2. Low Refrigerant Charge (Refrigerant Leak)

Refrigerant is the fluid that moves heat out of your home. When the charge is low due to a leak, not normal use the pressure inside the evaporator coil drops. Lower pressure means lower temperature. The coil surface drops below freezing even with adequate airflow, and ice forms.

This one matters because low refrigerant is always a leak. Refrigerant does not "run out" on its own. Topping it off without finding and fixing the leak is a temporary patch, not a repair.

3. Clogged Condensate Drain Line

Your AC pulls humidity out of the air as it cools. That moisture collects on the evaporator coil and drips into a drain pan, then exits through a condensate drain line. In Millwood's warm, humid summer stretches, that drain line handles a significant volume of water.

Algae, dust, and debris build up inside the line over time. When it clogs, water backs up into the pan. When the pan fills, it overflows onto your floor, into your wall, or through your ceiling if the unit is elevated.

Many homes in Millwood's established neighborhoods especially those built during the building activity of the late 1990s and early 2000s near the Millwood Historic District and along the Argonne Road corridor are now running systems that are 15 to 20 years old. Builder-grade equipment from that era is hitting the end of its service life, and drain systems that were never maintained are often the first thing to fail.

4. Dirty or Damaged Evaporator Coil

A coil caked with dust and debris cannot transfer heat efficiently. The surface temperature drops unevenly, ice forms in patches, and drainage becomes unpredictable. A physically damaged coil bent fins, corrosion can cause refrigerant leaks that compound the problem.

Before you call, here are a few safe checks you can do yourself. These will not fix the problem, but they help you understand what you are dealing with and give us useful information when you call.

• Turn the system off. If you see ice, shut the AC off at the thermostat. Switch the fan to "ON" (not AUTO) to let warm air circulate and melt the ice safely into the drain pan. Do not chip or pull at the ice.
• Check your air filter. Pull it out and hold it up to light. If you cannot see light through it, it is overdue for replacement. A clogged filter is the single most common cause of frozen coils.
• Check the drain pan. Look under or around the indoor unit for standing water. If the pan is full or overflowing, the drain line is likely clogged.
• Check supply and return vents. Make sure furniture, rugs, or closed doors are not blocking airflow to the system.
• Do not restart the system until the ice has fully melted and you have addressed the filter. Running a frozen system accelerates compressor wear.

When to call immediately: If you see water actively dripping onto electrical components, smell burning, or notice the circuit breaker tripping when the AC runs, call (208)916-1956) now. Those are not DIY situations.