LG Portable AC Error P1 — Water Full Fix

What it means

LG portable AC error P1 means the internal condensate tank is full and the unit has stopped to prevent overflow.
Drain the tank by removing the drain plug at the rear of the unit and directing the water into a bucket or drain.

How to Fix It

Locate the drain plug at the rear

On the back of the LG portable AC, locate the lower drain port (usually a small rubber plug or a port labelled Drain).
Place a shallow bowl or bucket under the port before removing the plug.
Remove the drain plug and drain the water

Pull or unscrew the drain plug and allow all water to drain out.
LG portable ACs can collect 1–3 litres per hour in humid conditions, so the tank can fill quickly.
Refit the drain plug firmly

After draining, refit and tighten the drain plug.
A loose plug will allow water to leak from the unit during normal operation.
Set up continuous drainage

LG portable ACs have a continuous drain port (upper port at the rear).
Attach the provided drain hose and direct it to a floor drain, sink, or out of a window.
With continuous drainage active, the tank never fills and P1 will not trigger.
Ensure the drain hose runs downhill

For gravity continuous drainage to work, the hose must run continuously downhill from the upper drain port.
A hose that rises at any point will cause water to back up and the tank will fill regardless.
Check the room humidity

In very humid conditions the LG portable AC collects large amounts of water.
If you are draining the unit multiple times per day, continuous drainage is the practical solution.

Frequently Asked Questions

LG portable AC P1 but I already drained it — why is it back so fast?

In high humidity conditions (above 70% RH), a portable AC can fill its tank in just a few hours.
Set up continuous drainage to eliminate the need to drain manually.

LG portable AC P1 error after setting up the drain hose — what is wrong?

Check that the drain hose is connected to the upper (continuous drain) port, not the lower (manual drain) port.
Also ensure the hose runs continuously downhill with no upward sections.

Does LG portable AC P1 mean the unit is working correctly?

Yes — P1 indicates the unit is successfully extracting moisture from the air (doing its job), but the tank needs emptying.
It is not a fault; it is a maintenance notification.