Meiko UPster U 400 M2 Error Codes ERR 302-303: Drain Level

What does MEIKO error code ERR 302 / 303 mean?

After a wash, the UPster U 400 M2 pumps the tank empty and the control watches the level sensing to confirm it is falling. ERR 302 and 303 report that, with the drain pump running, the tank water did not drop below the expected mark within the allowed time. 302 concerns level 1 and 303 level 3 of the tank sensing. The listed causes are a drain pump with low output, a dirty or defective pump, a loose impeller, or a failed capacitor. Debris in the pump or drain can restrict flow, a loose impeller spins without moving enough water, and a weak capacitor leaves the pump motor short of starting torque. In every case the machine is left holding water it cannot get rid of. The maker says it is not possible to continue and to call a technician. The operator can look at the sieves and the drain opening for visible debris, but the pump should not be opened or repaired by staff, since it sits in a wet area beside live electrical parts.

Affected models and control systems

This is for the Meiko UPster U 400 M2 glass and dishwasher. Other Meiko models and other controller generations use different drain error numbers.

Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.

What you may notice

• ERR 302 or 303 on the display
• Water left standing in the tank after a cycle
• A drain pump that hums, rattles or does not run

Possible causes

Listed in MEIKO's documentation

• Drain pump output
• Debris in the pump or the drain
• Loose impeller
• Pump capacitor

Other likely causes — what usually sits behind error code ERR 302 / 303 on this control. A technician confirms which one it is before any part is replaced.

• A broken glass fragment or label caught at the pump inlet
• Grease and food residue narrowing the drain hose
• A drain line that is partly blocked beyond the machine at the floor drain

Safe checks before calling for service

How a technician diagnoses error code ERR 302 / 303

1. Read the error and note which level mark failed.
2. Check the drain path outside the machine, including the floor drain.
3. Inspect the pump inlet for debris.
4. Check pump current and run the pump under load.
5. Test the capacitor and check the impeller fit.
6. Replace the pump or capacitor only after the tests.

How error code ERR 302 / 303 differs from similar codes

ERR 301 is the tank failing to fill; ERR 302 and 303 are the tank failing to drain.

Technical reference

Document

UPster U 400 M2 Original operating instructions 9760441 (update 2026-06), 9.6.1 Messages p.33-35

Edition

9760441 / Valid from: 2018-02 / Update: 2026-06

Models / control

UPster U 400 M2

Section

9.6.1 Messages: INFO table printed p. 33, ERR table pp. 34-35 (of 50)

Checked

October 2026

We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.