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A120

A120 - Shutoff valve can’t close error

Rheem · Air Conditioning

What does A120 mean?

The unit is indicating an error because the internal shutoff valve is unable to close properly. This may require service to fix the valve or its connections.

Common Causes

  • Shutoff valve malfunction
  • Wiring issue to the shutoff valve

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check the wiring connections to the shutoff valve.

  2. 2

    Unplug and then plug back in the shutoff valve to reset it.

  3. 3

    If the alarm continues, contact customer service for further assistance.

Browse all codes in this manual (48)
Verified technical data. Last updated: April 2026

Related Faults

1 beep1 beep - WiFi Soft Reset initiated3 beeps3 beeps - WiFi Hard Reset initiated3 red flashes3 red flashes — Communication error
Source: Rheem Air Conditioning
Open Manual (Page 33)Search more codes in this manual