Gas Safe: Electrode, gas valve, and PCB work on a gas boiler must be carried out by a Gas Safe registered engineer.
F.27 Meaning
According to the installation and servicing instructions manual, “safety switch-off: Flame simulation”. Also according to other sources, “Incorrect Flame Detection Fault (Flame Detection Even Though The Gas Valve Is Off)”
Cause of F27
According to the installation and servicing instructions manual. there is moisture on the electronics, electronics (flame monitor) defective, gas solenoid valve leaking. According to vaillant the causes are as follows.
- Damage On The Electrode Or The Ignition Lead
- Moisture Present On The Electronics
- Fault On The Spark Generator
- Fault On The Main PCB
Part Nos
Electrode (ignition/monitoring) 090709 Buy on Amazon Buy on eBay
Part numbers must be confirmed by a Gas Safe professional against the boiler GC number before ordering or fitting. 090709 replaced 090750 where applicable.
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