BoilerFaultCodesVokera E090 Fault Code
The Vokera E090 fault code means: your boiler has sensed that the exhaust fumes are getting too hot and has shut down as a safety precaution to prevent damage.. It appears on 4 Vokera models in our database.
Technical description: Flue gases over temperature probe
What causes the Vokera E090 fault?
This fault occurs when the internal temperature of the exhaust gases exceeds safe limits, potentially causing damage to the boiler's internal plastics. The most common reasons are a build-up of debris or limescale inside the heat exchanger, which prevents heat from transferring to the water, or a failure of the internal insulation panels meant to contain the burner's heat.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Vokera models that show the E090 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera E090 fault code information on this page is sourced and cross-checked against the official Vokera service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026