e004
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Navien · Tankless Water Heaters
False flame detection reported by control board.
Quick Answer
Error code E004 on your Navien Tankless Water Heaters means: False flame detection reported by control board.. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Verify dedicated grounding and electrical polarity.
2
Inspect flame sensor wiring connections.
3
Restart unit to clear transient detection.
4
If persistent, technician should test flame circuit and PCB.
5
Replace faulty components after diagnostic.
Pro Tip
This issue typically requires professional diagnosis. Attempting this fix without proper training could cause further problems.
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