Display shows E08 and heater does not heat; may be associated with very low or no water flow.

Safety: Turn off power at the breaker before removing covers or filters.

• Check water supply: Ensure the main cold water supply valve to the heater is fully open. Verify building water pressure is adequate.
• Clean inlet filter: Shut off water, relieve pressure by opening a hot tap, then remove and clean the inlet filter screen on the heater. Rinse thoroughly and reinstall.
• Clean aerators and showerheads: Remove and clean faucet aerators and showerheads that may be restricting flow. Soak in vinegar to remove limescale.
• Inspect flow sensor: If filters and aerators are clean, inspect the flow sensor for debris or scale as described for E01. Clean or replace if necessary.
• Test operation: Restore water and power, then open a large hot water tap fully. If E08 persists despite good flow, the flow sensor or control board may be faulty and should be checked by a technician.