BoilerFaultCodesPotterton A(5) Fault Code
Also written as A5 — same fault.
The Potterton A(5) fault code means: your boiler is unable to create the spark needed to light the flame, which means your heating and hot water will not work.. It appears on 3 Potterton models in our database.
Technical description: Igniter generator not working
What causes the Potterton A(5) fault?
This fault occurs when the boiler's internal computer sends a signal to start the fire, but no spark is physically generated to ignite the gas. The most common reason is that the electronic ignition component has failed or the spark electrode has become worn or cracked over time. Without this initial spark, the boiler cannot light safely and will shut down to prevent unburnt gas from building up.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Potterton models that show the A(5) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton A(5) fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026