E10 displayed; Sime water heater does not start and may indicate low water pressure or circulation fault.

Safety: Turn off power before opening any covers. Be prepared for water spillage when loosening connections.

Steps:

• Check mains pressure: Open a cold tap and verify strong flow. If house pressure is low, contact your water supplier.
• Verify isolation valves: Ensure the cold water inlet and hot water outlet valves at the heater are fully open.
• Clean inlet filter: Remove and clean the cold water inlet mesh filter as described in other entries.
• Inspect water pressure switch (if fitted): Some Sime models use a pressure switch on the water circuit. Check its wiring and ensure no leaks are present around it.

Professional help: If E10 persists with good water pressure, the internal pressure switch or hydraulic assembly may need replacement by a Sime technician.