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ON Twice Flashing

Water Saving Control OFF (Red LED) — Water saving control not active

Rheem · Tankless Water Heaters

What does ON Twice Flashing mean?

The red LED on the control board is flashing twice, and the display shows 'OF'. This means the water saving control is not currently active.

Common Causes

  • Water saving control not enabled or was reset.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off the gas and water to the water heater.

  2. 2

    Remove the front cover panel and ensure the remote is OFF.

  3. 3

    Locate DIP Switch 1 and ensure the third switch is in the ON position.

  4. 4

    Press the 'Max' or 'Min' button on the control board within 30 seconds.

  5. 5

    Verify the control board LED flashes ON once and the display shows 'ON'.

  6. 6

    Turn the gas and water supply back on.

Browse all codes in this manual (24)
Verified technical data. Last updated: April 2026

Related Faults

88Error 88 — Maintenance required before clearing codeAlarm/Error IndicatorSystem Alert — An issue has been detectedDANGER: Shock HazardDANGER: Shock Hazard — Electrical power is present
Source: Rheem Tankless Water Heaters
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