Vokera Vibe fault A90
Flue gas probe fault
Gas boilerWhat it means
Transitional alarm indicating a fault with the flue gas probe/sensor.
Likely causes
- Flue gas sensor/probe fault
- Faulty flue gas probe
- Wiring fault to flue gas probe
- Flue components incorrectly assembled, fixed or supported
- Flue or flue terminal obstructed
- Degraded seals around appliance burner, internal flue seals, door and case seals
- Mixing of combustion products and inlet air due to flue integrity failure
Where to start
- Press reset button for more than 2 seconds to attempt restart
- Insert fumes analysis probe until it reaches the stop
- Enter combustion analysis mode (press and hold >2 sec), display shows 'Co'
The full answer, free
- 30 more checks in order
- The readings and component tests from the manual
- How to put it right, step by step
- The manual page for this fault (page 28), right under the answer
Safety: Isolate gas and power before you open the case. If you have been into the gas side, do a tightness test, and a combustion and flue check before you hand back. Gas Safe (UK) or RGI (Ireland) work only.
From the Vokera manual for the Vibe. Check the model on the data plate before you order parts.
Other Vokera Vibe fault codes
- A10Flame lockout / condensate drain obstructed / flue gas exhaust/air suction obstructed
- A30Fan fault
- A40Fill the system
- A41Fill the system (transitional)
- A59High power supply voltage
- A60DHW probe fault
- A70Flow sensor fault / flow sensor overtemperature / flow/return sensor differential
- A80Return probe fault / return probe overtemperature / return-flow sensor differential
- A91Reset operating hours counter (related to fault A91)
- AF1Heating anti-freeze protection active
- AF2DHW anti-freeze protection active
- CFSService call signal / periodic boiler control
- E091Heat exchanger cleaning required (unusual usage threshold)
- SFSSTOP FOR SERVICE (permanent inhibition)