- Boilers
- Gas boiler
A02
Ferroli A02 on a gas boiler: flame signal with the burner off
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Ferroli A02 means the boiler detects a flame signal with the burner off and locks out. Reset once with the reset key for one second; if it returns, disconnect the boiler and call an authorised technician.
Safety first
Stop and check this first
- If you smell gas, do not reset: do not touch switches or light flames, open windows, close the gas valve if it is within reach, leave and call your distributor's emergency number from outside. Ferroli says to disconnect the boiler when it fails and have it repaired only by an authorised technician.
- Ferroli asks for the boiler to be disconnected when it fails and repaired only by authorised technicians with original parts. Do not clean or move the electrode yourself.
Safe checks you can perform
- One reset with the reset key
- When the code appears
- Ionisation circuit check
Leave these tasks to a qualified professional
- Do not attempt this professional task: Electrode and cable insulation test
- Do not attempt this professional task: Operating test and final analysis
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Electrode and cable insulation test
What they doThe technician checks with a multimeter whether the ionisation electrode or cable shorts to earth and inspects its condition.
They must show youthe measurement and the electrode inspected.
In writingwhat was found and what was replaced.
Operating test and final analysis
What they doAfter the repair, the technician runs several ignitions and a combustion analysis.
They must show youignitions without A02 and the analyser printout.
In writingthe date, the values and any part replaced with the reason.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
One reset with the reset key
- Who:
- you.
- How:
- press the reset key for one second, as Ferroli says for A lockouts.
- Result that matters:
- whether the boiler restarts and A02 does not return at the next ignition.
- If it restarts:
- note the date and whether it was raining or very humid.
- If A02 returns:
- Ferroli says the fault must be fixed; disconnect the boiler and call an authorised technician.
- Evidence to keep:
- a photo of the display with A02 and the date.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
When the code appears
- Who:
- you.
- How:
- note whether A02 appears on heat demand, with the boiler idle or after very humid days.
- Result that matters:
- a pattern that helps the technician separate moisture, trap or board.
- If it appears with humidity or heavy condensation:
- it points to the electrode, cable or trap.
- If it appears with no pattern:
- tell the technician; the board joins the list.
- Evidence to keep:
- a list of dates and circumstances.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
Ionisation circuit check
- Who:
- authorised gas technician.
- How:
- checks the ionisation electrode's wiring and condition, tests for shorts to earth and checks the trap and the board.
- Result that matters:
- where the false flame signal comes from.
- If there is a short to earth or a damaged electrode:
- that confirms it.
- If the circuit is fine:
- it points to the trap or the board.
- Evidence to keep:
- a report with what was measured and any part replaced.
The electrode and board sit in the gas circuit with mains voltage: Ferroli reserves repairs for authorised technicians.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Boilers
- Brand
- Ferroli
- Product type
- Gas boiler
Known code variants
- A-02
- A2
- Anomalía A02 Ferroli
- Beretta A 02
- Ciao Green A02
- Cointra A 02
- Error A02 Beretta
- Error A02 Cointra
- Error A02 Ferroli
- Ferroli A02 caldera
- Superlative A02
What it means
On the BlueHelix Tech RRT, A02 is "flame signal present with the burner off": the control sees a flame when there should be none and locks out for safety. Ferroli lists as causes an electrode fault (ionisation electrode wiring or condition), the electrode or cable shorting to earth, the condensate trap, which it says to check, and a board fault. It is a permanent lockout reset with the reset key. The code does not say which cause is acting.
Warnings and stop conditions
- Criticaleditorial warning
If you smell gas, do not reset: do not touch switches or light flames, open windows, close the gas valve if it is within reach, leave and call your distributor's emergency number from outside. Ferroli says to disconnect the boiler when it fails and have it repaired only by an authorised technician.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
- Highsource verified
Ferroli asks for the boiler to be disconnected when it fails and repaired only by authorised technicians with original parts. Do not clean or move the electrode yourself.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
Symptoms and causes
Probable causes · in order
- Ionisation electrode or cable shorting to earthPossible
Ferroli lists the electrode and cable to earth. Moisture or damaged insulation give a false signal; measuring confirms it.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
- Condensate trapPossible
Ferroli says to check and clean the trap. If the code coincides with heavy condensation, it is a candidate.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
- Control boardLess common
Ferroli says to check the board. It comes last, once electrode, cable and trap are fine.
Evidence: Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
Virtual technician
Does A02 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Ferroli BLUEHELIX TECH RRT 28 C instrucciones de uso instalación y mantenimiento
Ferroli · 2018 · manual
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