BoilerFaultCodesRemeha E04 Fault Code
The Remeha E04 fault code means: your boiler is failing to light or stay lit, meaning it cannot safely generate heat and has locked itself out.. It appears on 8 Remeha models in our database.
Technical description: Flame failure (loss of flame during operation or 5 unsuccessful start attempts)
What causes the Remeha E04 fault?
This fault occurs when the boiler's control system cannot detect a steady flame after trying to ignite several times. The most common reasons are a worn-out ignition spark, a dirty sensor that can't 'see' the flame, or an unstable gas supply preventing a smooth arrival of fuel. Without a confirmed flame, the boiler shuts down as a safety precaution to prevents unburnt gas from building up.
This fault is more common during the first cold snap of autumn when components that have sat idle all summer are suddenly forced to work under high demand.
DIY fix possible
Check that your gas meter has credit (if on a prepay meter)Check that other gas appliances in the home are working correctlyPress the 'Reset' button on the boiler control panel for 2-3 seconds
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Gas Safe Register →Remeha models that show the E04 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Remeha E04 fault code information on this page is sourced and cross-checked against the official Remeha service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026