Unit displays E8 and shuts down; may occur during long draws of hot water
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Turn OFF power and allow the unit to cool. Do not attempt to operate the heater without confirmed water flow.
Steps:
- 1. Verify valves: Confirm that the cold water inlet and hot water outlet isolation valves are fully open.
- 2. Bleed air: Open several hot water taps in the home to purge air from the lines. Let water run until a steady stream is achieved.
- 3. Clean inlet filter: Remove and clean the cold water inlet filter screen. Debris here can cause low flow and trigger dry-fire protection.
- 4. Check flow sensor: Inspect and clean the flow sensor turbine as described for E4. Ensure it spins freely.
- 5. Reset and test: Restore power and run hot water. Monitor for E8. If it recurs with good flow, the flow detection or dry-fire circuit on the PCB may be faulty.
Professional help: Persistent E8 errors after confirming proper plumbing and flow require PCB-level diagnosis by a technician.
Repair Difficulty
Required Part
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