Diagnosis
The E02 code is the pressure washer's way of saying it thinks the inlet water supply is insufficient or blocked. It's a safety lockout to protect the pump from running dry.
How to Fix It
First, make sure your garden hose is turned on all the way at the spigot. Then, check the inlet water filter screen. Unscrew the hose connection from the washer's inlet. You'll see a small plastic filter basket inside. Pull it out, rinse off any debris, and put it back in. Reconnect the hose tightly, turn the water on fully, and try again. The code should clear once it detects proper flow.
If That Didn't Work
If the code persists, the issue might be with the flow sensor itself. Try using a different garden hose, one you know has good flow. Sometimes a kinked or old, collapsing hose can trigger this even if the spigot is on.
Heads Up
This unit needs a minimum water flow to operate. Don't try to bypass this by starting it without water hooked up—you'll destroy the pump seals in seconds.