Emergency
E031 on Navien NCB300

Your boiler has detected that it is running much hotter than it should be and has switched itself off to prevent damage.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Overheating of Burner

From this model's manual
Verified against the Navien/Navien Ncb300 Combi Service Manual30k 250328 Pdf installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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All 56 fault codes on the NCB300

Seeing a different code? Every code this model can display, in one place.

001003004004E012012E016016E030030E031046047109109E205302407515517593594615740782E001E003E004E012E016E030E046E047E109E110E205E218E302E351E352E353E407E421E439E515E517E593E594E598E615E740E782E783E787E788

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