CodeRegistry
Brands
  1. Home
  2. Mitsubishi Electric
  3. Air Conditioning
  4. E1, ER1, ET1
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

E1, ER1, ET1

Error E1, ER1, or ET1 — General error code

Mitsubishi Electric · Air Conditioning

What does E1, ER1, ET1 mean?

These codes indicate a general error with the air conditioner system. The specific meaning can vary and may require referring to detailed service information.

Common Causes

  • General system malfunction
  • Specific component failure
  • Configuration error

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Try resetting the air conditioner by turning the power off at the breaker for several minutes, then turning it back on.

  2. 2

    If the error code persists, consult the service manual or contact customer support for specific diagnostic procedures related to E1, ER1, or ET1.

  3. 3

    Ensure the correct refrigerant is used, as specified in the manual.

Browse all codes in this manual (170)
Verified technical data. Last updated: April 2026

Related Faults

0.5-second ON / 0.5-second OFF blinkUpper lamp blinks 0.5-second ON/OFF - Miswiring or serial signal error00Normal operation - No error codes1 beep during error display mode1 beep during error display mode - Unit has an error (different code)
Source: Mitsubishi Electric Air Conditioning
Open Manual (Page 2)Search more codes in this manual