Unit displays E8 and shuts down; may be accompanied by very low or no water flow.

Safety: Turn OFF power at the breaker before opening the unit. Water-side work can usually be done with power off only.

• Verify plumbing valves: Confirm the cold water shutoff to the EcoSmart heater is fully open. Check any isolation valves on the hot outlet as well.
• Clean inlet filter: Remove and rinse the inlet filter screen at the cold water connection to remove sediment and debris.
• Check fixtures: If you are using ultra-low-flow aerators or showerheads, temporarily remove them and test again. The heater may require a minimum flow (e.g., 0.3–0.5 GPM) to activate.
• Inspect flow sensor: With water off, remove and inspect the flow sensor for scale or debris. Clean with vinegar if necessary and reinstall.
• Test operation: Restore water and power, then open a hot tap fully. If E8 persists despite good flow, the flow sensor may be failing and should be replaced.