my costway portable ac is blowing air but it's not cold at all, just feels like a fan. what gives?

Diagnosis

When a Costway EP24618US blows air that isn't chilled, the unit has effectively reverted to "Fan Only" mode. This happens when the compressor—the heart of the cooling system—fails to engage or cannot dissipate heat. If the compressor isn't running, the refrigerant cannot undergo the phase change necessary to absorb heat from your room, leaving you with nothing but a glorified desk fan. The most common root cause for this specific model is "thermal overload." Because portable ACs are single-hose systems, they create negative pressure in the room. If the exhaust hose is kinked, partially blocked, or improperly sealed at the window, the hot air expelled by the condenser is pushed back into the unit or the room. This causes the internal components to overheat, triggering a safety switch that shuts down the compressor to prevent permanent motor burnout while allowing the fan to keep spinning. You can confirm this by touching the exhaust hose; if it isn't scorching hot to the touch while the unit is running, the compressor is likely off.

How to Fix It

To restore cooling functionality, you must ensure the heat exchange cycle is unobstructed and the compressor is reset. Follow these precise steps:

1. Power down the unit completely and unplug it from the wall outlet for at least 30 minutes. This allows the compressor's thermal overload protector to reset and the internal coils to cool down.
2. Inspect the exhaust hose from the back of the unit to the window. Ensure there are no sharp bends, kinks, or heavy objects resting on the hose. A bend of more than 45 degrees can restrict airflow enough to trip the overheat sensor.
3. Detach the hose from the rear of the AC. Inspect the coupling ring for cracks. Reinsert the hose firmly into the outlet and rotate it clockwise until it locks with a definitive click.
4. Examine the window slider kit. Ensure the hose is locked into the adapter and that the adapter is snugly fitted into the window track.
5. Apply the included adhesive foam weather-stripping to any gaps between the window sash and the slider. If hot outside air leaks back in, the unit will struggle to drop the room temperature, making the air feel "room temperature" rather than cold.
6. Plug the unit back in and set the mode to "Cool," the fan speed to "High," and the temperature to its lowest setting (usually 60°F or 16°C). Wait 3-5 minutes for the compressor delay timer to engage.

If That Didn't Work

• Check the air filter located behind the front grille. If the filter is clogged with dust and pet hair, the evaporator coils cannot get enough airflow to cool. Remove the filter, wash it with lukewarm soapy water, dry it completely, and reinstall. A dirty filter is a primary cause of "fan-only" behavior.
• Drain the internal water reservoir. While this model often evaporates condensate, high humidity can overwhelm the system. Locate the drain plug at the bottom rear, place a shallow pan underneath, and remove the plug. If the internal tank is full, some versions of the EP24618US will disable the compressor to prevent leaking.
• Verify your power source. Portable ACs draw significant amperage. If you are using a thin extension cord or a power strip, the compressor may not be receiving enough voltage to start, even if the fan is running. Plug the unit directly into a grounded 120V wall outlet.
• Inspect for refrigerant leaks. If the exhaust hose is hot but the air coming out of the front is still warm, the unit may have a puncture in the copper tubing or a leak at the service valve. Look for oily residue on the coils; if you see oil, the refrigerant gas has escaped and the unit requires professional recharging or replacement.

Heads Up

• Never operate the unit without the exhaust hose connected to a window; doing so will overheat the compressor in minutes and may void your warranty.
• Clean your filters every two weeks during peak summer usage to maintain airflow efficiency and prevent ice buildup on the coils.
• Avoid using "Cool" mode if the room temperature is already below 60°F, as this can cause the evaporator to freeze, blocking airflow entirely.
• Always keep the unit at least 20 inches away from walls or furniture to ensure the intake vents have sufficient clearance for air circulation.