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How Often to Change Your AC Filter in Las Vegas: A Frozen AC in Henderson

In Las Vegas, check a standard 1-inch filter every month during cooling season and change it at least every 1 to 3 months, more often with pets, construction nearby, or a dusty yard. Desert dust and long summer run times load filters faster here than the label on the box assumes. On August 18, 2026, we saw what happens when one goes too long at a Henderson home in the 89074 ZIP. The AC had stopped cooling, the indoor unit had iced over, and water was dripping in the closet as the ice melted. The filter was packed solid with dust.

What We Found

The air handler sits in a closet, and the outdoor unit is a Ruud condenser. The filter was caked with a thick gray layer of dust across its whole face. With that little air getting through, the indoor coil can get cold enough to freeze, and this one had: ice coated the refrigerant piping at the bottom of the air handler, and water was beading on the cabinet and staining the area near the access panel as it thawed. A towel was already down to catch the drips.

How We Fixed It

Had the homeowner turn the AC off for 4 to 6 hours so the ice could melt completely.
Walked through replacing the dirty filter with a clean one and laying towels to catch the meltwater.
Set the restart for around 8:30 that evening, with instructions to watch whether the house cools.

How it turned out

The plan was to restart the system after the thaw with a clean filter in place. A follow-up call was set only if the AC still didn’t cool once it was back on.

Why does a dirty filter freeze an AC?

The indoor coil needs a steady flow of warm house air across it to stay above freezing. Choke that airflow and the coil drops below 32 degrees, moisture in the air turns to ice, and the ice blocks even more air. Low refrigerant can cause the same freeze, so if a clean filter doesn’t solve it, the system needs testing. More in our AC filter myths page.

Can I run the AC while it’s frozen?

Turn cooling off until the ice is gone. Running a frozen system keeps it from cooling and can send liquid refrigerant back to the compressor, which is hard on it. Setting the thermostat to Off, or to Fan only, lets the ice melt.

Which filter should I buy?

Use the size and rating your system is designed for. Higher-rated pleated filters catch more dust, which also means they clog sooner, so they need the same monthly check. If you can’t see light through the filter, change it.

Safety note: HVAC repairs involve high voltage, refrigerant and, on gas furnaces, combustion gases. Leave them to a licensed technician.

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