Ferroli [A01] fault codewhat it means and how to fix it

A01 is no burner ignition, and being an A code it is a permanent lockout that needs a manual reset. The Ferroli manual gives five causes: no gas, a detection or ignition electrode fault, a defective gas valve, incorrect inlet gas pressure, and an obstructed siphon. That last one deserves attention because Ferroli name it explicitly where many manufacturers leave it implied. The siphon is the condensate trap — the U-bend inside the appliance that holds a water seal and lets acidic condensate drain away while stopping flue gases coming back through the drain.

When it blocks, condensate backs up into the combustion chamber and the burner cannot stay alight. The same thing happens when the external condensate pipe freezes, which is why winter produces so many of these. A blocked siphon and a frozen drain present identically, and one of them you can fix from outside with a kettle of warm water.

1. 1

   Try a gas hob. If it will not light, the supply is the problem and the appliance is behaving exactly as it should.

2. 2

   Check any prepayment meter for credit, including emergency credit that may have run out overnight.

3. 3

   Outside, follow the plastic condensate pipe down from the appliance and feel for a solid, ice-cold section. Bends and the open end freeze first.

4. 4

   Pour hand-hot water slowly along any frozen section until you hear it running clear. A kettle boiled and left standing ten minutes is about the right temperature.

   Never use boiling water, a heat gun, or a naked flame. Cracked plastic in freezing weather is a considerably worse problem than the one you set out to fix.
5. 5

   Press reset for a second. If it lights and holds, the condensate was the cause. If it locks out again, the siphon inside may be blocked and that needs an engineer.