Vokera Flame Signal Instability

Boiler displays 27, intermittent lockouts, may relate to ionisation/flame signal

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Poor earth, Contaminated burner, Incorrect gas/air ratio, Faulty flame sensing circuit on PCB

Safety first: Turn off power and gas. Combustion adjustments must be done by a Gas Safe engineer.

Check electrical earth: Ensure the boiler is properly earthed at the spur and consumer unit.
Engineer tasks:
- Clean burner and check for corrosion or debris.
- Verify gas valve settings with a flue gas analyser.
- Check flame sensor and wiring.
- Test PCB flame detection circuitry.

Do not attempt to adjust gas valves without proper equipment and certification.

Professional Required 5/5

Main PCB (Flame Detection Circuit)

Check Price on Amazon

We may earn a commission from links on this page.