Vokera Synergy fault E091

What it means

The appliance monitors operating conditions and records 'unusual usage conditions' that affect the requirement to remove and clean the burner/heat exchanger assembly. When the unusual usage hours reach a pre-determined threshold, the appliance signals via alarm code E091 that the heat exchanger requires cleaning.

Likely causes

1. Primary heat exchanger requiring cleaning (related to fault E091)
2. Primary heat exchanger hour counter exceeded 2500 hours threshold (fouling/cleaning interval reached)
3. Primary heat exchanger fouled/dirty
4. Scale or deposits in primary heat exchanger
5. Accumulated unusual usage hours reaching pre-determined threshold
6. Burner/heat exchanger contamination due to operating conditions
7. Flue components incorrectly assembled, fixed or supported
8. Flue or flue terminal obstructed
9. Degraded seals around appliance burner, internal flue, door or case
10. Maximum flue lengths exceeded or guidance (e.g. Technical Bulletin 008) not followed
11. Analyser not zeroed/calibrated correctly before use

Where to start

1. Access the INFO menu, item I015 to display the value of the flue gas probe hour counter (display/100, example 2500h = 25)
2. Using the UI menu, navigate to the alarms history and check for recent alarm events
3. Remove front cover and visually inspect internal components