Error A23 in Ferroli boiler: what it means and how to act

Introduction

The A23 error in a Ferroli boiler indicates an anomaly in the electronic board parameters (PCB). Practically, the unit detects that its internal configuration does not match what is expected and protects itself by locking out heating and domestic hot water. This is usually an electronic issue related to board programming or memory rather than a simple hydraulic or combustion fault. Resetting may help only in a few temporary cases; if the code returns, professional inspection, reprogramming or board replacement is normally required. If you have a problem with your boiler, you can use our free error code finder to identify and address errors quickly and effectively.

What A23 means in the boiler electronics

The A23 code points to a parameter fault in the PCB, not to a combustion failure or classic hydraulic problem. The control unit detects that the information stored or loaded on the board does not match the expected values and, for safety, prevents the boiler from continuing to operate. Because the PCB coordinates ignition, combustion, safety interlocks and modulation, a configuration error or corrupted memory causes the appliance to go into lockout to avoid unsafe operation.

Typical symptoms

• The boiler refuses to operate for central heating and/or domestic hot water.
• Repeated attempts to start may result in immediate stop or cycling without ignition.
• No clear hydraulic or combustion clues (pressure, visible flame problems) — the fault is in the control layer.
• The display shows A23 and the unit remains protected until the parameter issue is resolved.

Common causes and triggering circumstances

The most frequent causes of A23 are:

• Incorrect PCB configuration: after a board replacement, software update, or previous repair where parameters were not set correctly.
• Memory corruption or internal board fault: damaged memory, failed control circuitry or other component-level failures on the PCB.
• Electrical incidents: voltage drops, micro-outages, surges or unstable supply that alter stored parameters or damage sensitive electronics.
• Bad contact or wiring faults: in some cases a poor connection can mimic parameter errors.

What to check before assuming the board is faulty

Perform these simple checks to help determine whether the fault is temporary or persistent:

• Power-cycle the boiler: switch off the mains supply for a few minutes and restart. A single transient error may clear.
• Note recent events: power cuts, interventions, part replacements or long shutdowns. If A23 appears immediately after a repair, suspect incorrect parameterization or an unsuitable replacement board.
• Check the household electrical environment: have other appliances experienced fluctuations or damage?
• Avoid repeated resets or persistent restart attempts — these rarely fix internal configuration faults and only add wear to the electronics.

When to call technical assistance

If the error does not disappear after a proper reset, or if it reappears repeatedly, professional inspection is required. A technician must:

• Read the fault code and record the unit’s behavior.
• Verify the electrical supply, wiring continuity and connections to rule out external causes.
• Access the PCB to check parameter consistency and whether the board retains configuration data.
• Decide between reprogramming/restoring factory parameters and replacing the PCB based on memory health and component condition.

Attempting to open or tamper with the PCB without specific training is not recommended: the board contains sensitive components and memory that can be further damaged, increasing repair costs.

How diagnosis is performed (home visit or workshop)

1. Confirm the presence of A23 and the exact model/version of the boiler.
2. Check mains voltage, earth, and the stability of the supply at the installation.
3. Inspect wiring, connectors and adjacent components for faults or corrosion that could affect readings.
4. Access the PCB and attempt to read stored parameters; check whether values match the model’s expected configuration.
5. If accessible, restore factory settings or load the correct configuration for that model and test operation.
6. If the board will not retain settings or shows hardware faults, recommend replacement with a compatible and properly parameterized PCB.

Possible solutions and usual interventions

• Simple reset: may clear a transient error after a power incident.
• Restore factory parameters / reprogram: when the board can still read and write data, loading the correct configuration often fixes the issue.
• Repair or replacement of the PCB: necessary when memory or control circuits are irreversibly damaged.
• Check and repair connections or wiring: a bad contact can mimic a major electronic fault.
• Improve electrical protection: install surge protection or stabilise the supply if the installation is prone to voltage events.

Which option is selected depends on the model architecture, component availability and the technician’s judgment. A careful diagnosis can avoid unnecessary part replacements and save time and cost.

What A23 indicates about the boiler’s overall condition

A23 is often a sign that the boiler’s electronics are entering a fragile state. It can reflect either a recoverable misconfiguration or deeper PCB deterioration. Because modern condensing boilers rely heavily on electronic control, repeated electrical stress (surges, drops, micro-outages) accelerates wear and increases the chance of parameter corruption. After resolving the fault, it is sensible to verify the electrical installation and consider protective measures to reduce recurrence.

Risks of leaving the error unchecked

Ignoring an A23 error typically does not make it disappear. Potential consequences include:

• Intermittent or unpredictable boiler operation.
• Erratic starts or repeated lockouts leaving the home without heating or hot water.
• Progressive damage to electronics if the underlying electrical problem persists.
• Higher repair costs if attempted amateur fixes worsen the PCB condition.

Quick reference

• Code: A23
• Description: Anomaly in electronic board parameters (PCB)
• Typical causes: incorrect configuration, memory corruption, internal PCB failure, electrical incidents
• Usual solution: reset (temporary), reprogram/restore parameters, or replace PCB after technician diagnosis

Final recommendations

Do a controlled power-cycle as an initial test and collect any context (recent repairs, power events) before calling a technician. Do not repeatedly force restarts. If A23 persists, arrange for qualified service to diagnose the PCB, verify parameter integrity and either reprogram or replace the board as required. After repair, consider stabilising the electrical supply and using surge protection to reduce the risk of recurrence.