-
1
Check the display or control panel
Look at the heater screen or controller. If E8 error code is displayed, the system has detected abnormal water circulation and entered safety protection mode.
Common Signs:E8 error code shown Heater shuts down shortly after starting Display remains on but heater does not run -
2
Confirm water supply and pressure
Ensure the incoming water supply is fully open. Low water pressure or restricted flow can cause the pump to operate abnormally and trigger an E8 fault.
Check for:Main water valve fully open No blocked filters or strainers Normal water pressure at other taps -
3
Test hot water flow
Turn on the hot water tap fully. If water flows but stays cold, the heater is not igniting or is shutting down during operation.
Typical symptoms:Water flows but stays cold Heater cuts off after ignition Error returns repeatedly -
4
Listen for pump and fan operation
When the tap is turned on, you should hear the fan and internal pump running smoothly. Unusual noise, weak operation, or silence often indicates a failing pump.
Warning Signs:No pump sound Loud or grinding noise Intermittent operation -
5
Stop using if E8 error persists
If the E8 error code continues after basic checks, avoid repeated resets. A faulty pump can cause overheating and internal damage. Arrange a licensed gas inspection to assess repair or replacement.
Important:Heater not working Do not force restart Book inspection
