Eldom heater shows E10; unit may not fill or may shut down when hot water is drawn.

Safety: Never power an electric water heater with an empty tank; the element can be destroyed quickly.

Steps:

• Verify water supply: Ensure the cold water inlet valve to the heater is fully open. Check building water pressure.
• Bleed air: Open the nearest hot water tap fully. Allow water to run until all air sputtering stops and a steady stream flows.
• Check non-return/safety valve: Inspect the Eldom inlet combination valve (safety/pressure relief with check valve). A stuck check valve can prevent proper filling; replace if suspected.
• Reset the heater: After confirming the tank is full and air-free, turn power back on and see if E10 clears.
• Control fault: If E10 persists despite proper filling, the internal dry-fire detection or flow sensing circuit on the control PCB may be faulty and require board replacement.