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In-Use Indicator Lit

In-Use Indicator Light is Lit - Water heater is operating

Rheem · Water Heaters

What does In-Use Indicator Lit mean?

When the 'In-Use' indicator light is lit, it means the water heater is actively heating water. This is a normal operating status.

Common Causes

  • Water heater is in its heating cycle.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    No action is typically required when the In-Use indicator is lit, as it signifies normal operation.

  2. 2

    If you suspect an issue, check the temperature setting.

  3. 3

    Ensure there is sufficient hot water demand.

Browse all codes in this manual (70)
Verified technical data. Last updated: April 2026

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Source: Rheem Water Heaters
Open Manual (Page 55)Search more codes in this manual