Can I reset my Navien boiler to clear the E004 code?

You can reset once if your manual says it's safe. If the code returns, stop resetting — repeated resets on a genuine fault, especially gas or overheat faults, can be unsafe and may worsen the problem. Book a licensed repair instead.

Is the E004 fault dangerous?

Treat it as urgent. This code involves systems where continued operation can be unsafe. Turn the boiler off if it keeps recurring and call for a licensed repair; if you smell gas, leave and call your gas utility's emergency line.

How much does it cost to fix a Navien E004 fault?

Cost depends on the underlying cause — some causes (like low pressure or a dirty sensor) are minor, while others (like a gas valve or control board) cost more. We diagnose first and give you a clear price before any repair.

Navien Error Code

Navien Error Code E004

False flame detected — the boiler senses a flame when it should be off.

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Licensed & Insured Gas-Certified Technicians Serving Vancouver Since 1999

If your Navien combi boiler is showing error code E004, here's what it means: False flame detected — the boiler senses a flame when it should be off. This is an urgent fault. Stop using the boiler if it keeps recurring and book a licensed repair promptly — especially if it involves gas, ignition, overheating or the flue.

Navien boilers report faults using e-series codes (e.g. e003, e110). Knowing the code helps a technician arrive prepared with the right parts, which usually means a faster, lower-cost repair.

What causes the E004 code?

Error E004 on a Navien boiler is most commonly caused by one of the following:

Faulty flame-sensing electrode
Damp or shorted wiring
Control board fault

What you can safely check first

Note the exact code and your boiler's model number
Check the pressure gauge — low pressure triggers many faults
Confirm the gas supply is on and other gas appliances work
Reset the boiler once, per the manual, only if it's safe to do so
If the code returns, stop and call a licensed technician

Why this needs a licensed technician

Resolving a E004 fault almost always involves the gas, combustion, sensor or pressurized side of the appliance. Under BC's Safety Standards Act, that work must be performed by a licensed gas fitter — and doing it correctly protects your warranty and your safety. We diagnose Navien boilers, carry common parts, and verify clean combustion before returning your boiler to service.

Smell gas or suspect carbon monoxide? Leave now.

If you smell gas, hear hissing, or your CO alarm sounds, leave the building immediately and call your gas utility's emergency line from outside. Do not operate switches or relight the appliance. Once you are safe, call us for a licensed repair.

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Frequently Asked Questions

Other Navien codes & help

Navien E003Ignition failure — the boiler tried to light but no flame…Navien E012Flame loss during operation — the burner lit but the flam…Navien E016Overheating — water temperature exceeded the safe limit.Navien E030Exhaust (flue) temperature too high.Navien E041Water flow sensor / low flow fault on the DHW side.All Navien Error CodesFull list

Fix Your Navien E004 Fault

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