What Does P1 Mean on AC?

Updated: Feb 15, 2024 5:15 PM


The last thing any AC owner wants to find is a confusing message on their unit’s display panel. But don’t worry because the best air conditioners often show error codes to point users toward fixable issues before further damages occur. A P1 error code on a portable air conditioner means there’s a problem with the water level or drainage. It happens when the water in the air conditioner’s tank gets too high. This could be because the drain is blocked or not working right. To fix the P1 error, you need to clean the drain and make sure the water can flow out properly.

Below, we’ll discuss in more detail about what does P1 mean on an air conditioner and what you can do about it.

Key Takeaways_

  • The P1 error code is common with portable AC units, indicating that the drain pan is full.
  • When you receive the P1 code, immediately empty the drain tray and check for any clogged drain lines or a broken drain plug.
  • P1 can also indicate that there is something wrong with the electrical flow of your AC unit, such as a voltage surge.

While this article focuses on portable units, we’ve another excellent article for homeowners wondering what is wrong with their central air conditioner.

What P1 Means on an AC Unit

The P1 error code most commonly occurs with portable air conditioners and typically indicates a full drain tray that needs to be emptied. So, it won’t tell you if your AC sensor is not working.

insider tip

If you receive a P1 code as a voltage issue, turn the unit off, wait about 5 minutes, and turn it back on again to see if it fixes the problem.

The drain tray sits at the bottom of your portable air conditioner, capturing the condensate that drips from the evaporator coils. Check the tray frequently because how quickly it fills depends on humidity, air temperature, and coolant levels. For more info on AC components, check out our article explaining what evaporator coils do. You may also be interested in learning about how portable air coolers work.

Keep in mind, however, that there is no universal air conditioner error code system, and P1 might not always indicate a full water pan. Another less-common meaning of P1 is that there is something wrong with the voltage (either too low or too high). Therefore, before making any assumptions, consult your user manual to confirm what the P1 error code means. If you can’t find the code in the manual, search online or call the AC manufacturer.


Be careful whenever moving a portable AC with a full drain tray. The water can splash around and get on the floor or the internal electronics.

And if you think your unit is beyond repair and want to learn more about the various AC units, read our article explaining what a ventless air conditioner is. Also, ensure that you understand the BTU meaning for an AC before purchasing a new model so that you know you’re getting an AC that is sized correctly for your space.

Emptying the Drain Pan

Assuming your unit displays the P1 code because of a full drain pan, examine the drain line to see if it’s clogged. If so, you’ll need to clean it out. Then test the drain plug to see if it’s functioning correctly. Lastly, check the drain hose to ensure it’s free of holes or kinks.

STAT: Depending on environmental factors and usage, a portable AC drain tray can take anywhere from 6 hours to several weeks to fill. (source)

If you are worried that the P1 code might be an electrical issue, you can get a multi-meter and test the voltage if you’re comfortable doing so. Otherwise, you may need to call a technician.

Nathan Rizzuti Avatar

Learn More About Air Conditioners