- Boilers
- Gas boiler
A02
Beretta A02 on a gas boiler: limit thermostat alarm
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Beretta A02 is the limit thermostat alarm, a permanent lockout. Read the pressure gauge, reset once by turning the selector to OFF for 5 to 6 seconds and, if A02 returns, call the technical service.
Safety first
Stop and check this first
- If you smell gas: Beretta says not to touch electrical switches, the phone or anything that sparks, to ventilate by opening doors and windows and to close the main gas tap. Then leave the home and call your gas distributor's emergency number from the street.
- Do not chain resets with A02: it is a temperature safety cut. If it returns, leave the boiler on OFF and wait for the technical service.
Safe checks you can perform
- Pressure gauge reading
- One reset with the selector
- When the code appears
- Thermostat and circuit check by the technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Limit thermostat check
- Do not attempt this professional task: Circulation and pressure check
- Do not attempt this professional task: Combustion analysis after the repair
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.
Limit thermostat check
What they doWith the boiler cold, the technician checks the limit thermostat and its connection are closed as they should be.
They must show youthe thermostat test with the boiler cold.
In writingthe result and, if it is replaced, the part reference and why.
Circulation and pressure check
What they doThe technician checks pressure, venting and that the main heat exchanger is clean, as Beretta's maintenance list asks.
They must show youthe gauge pressure and the heat exchanger condition.
In writingwhat was checked and corrected.
Combustion analysis after the repair
What they doUsing the combustion analysis function, the technician measures the flue gases at the test point and compares them with the maker's table.
They must show youthe analyser printout.
In writingthe measured values against Beretta's.
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.
Pressure gauge reading
- Who:
- you.
- How:
- with the boiler cold, read the gauge. Beretta asks that pressure stays at or above 1 bar.
- Result that matters:
- whether pressure is around 1 to 1.5 bar.
- If it is below 1 bar:
- top up with the filling tap to 1 to 1.5 bar with the selector on OFF, as Beretta describes, and tell the technician.
- If it is correct:
- lack of water does not explain A02; carry on with the other checks.
- Evidence to keep:
- a photo of the gauge with the date.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
One reset with the selector
- Who:
- you.
- How:
- turn the function selector to off (OFF), wait 5 to 6 seconds and turn it back to summer or winter, as Beretta describes for A02. Do it once.
- Result that matters:
- whether the boiler starts and the code stays away.
- If it starts and does not come back:
- note the date and time; if it repeats another day, tell the technical service.
- If A02 returns or the boiler does not start:
- do not keep trying; Beretta says to call the technical service.
- Evidence to keep:
- a photo of the display with the code and a note of each reset.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
When the code appears
- Who:
- you.
- How:
- note whether A02 comes up after heating for a while or right at start up.
- Result that matters:
- when it trips.
- If it trips after heating for a while:
- tell the technician; it points to real overheating.
- If it trips cold:
- it points to the thermostat or its wiring.
- Evidence to keep:
- a note of the time and what the boiler was doing.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
Thermostat and circuit check by the technician
- Who:
- technician from the technical service.
- How:
- checks the limit thermostat, its wiring and water circulation in the boiler.
- Result that matters:
- whether the cut was real temperature or a thermostat fault.
- If there is real overheating:
- find out why the water is not carrying the heat away.
- If the thermostat fails without overheating:
- it is checked or replaced.
- Evidence to keep:
- a report of what was checked and any part replaced.
Beretta reserves servicing and maintenance for qualified staff of its technical service: opening the boiler or touching sensors, fan or gas parts is not the user's job.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
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
- Beretta
- 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
In the Ciao Green C.S.I. table, A02 is the limit thermostat alarm and leaves the boiler in a permanent lockout. The limit thermostat is a safety device on the primary circuit that shuts the boiler down when the water gets hotter than intended. Beretta gives the same reset for A01, A02 and A03: selector to OFF, wait 5 to 6 seconds and back to the chosen position. The code does not say whether the water really overheated or the thermostat or its wiring failed.
Warnings and stop conditions
- Criticaleditorial warning
If you smell gas: Beretta says not to touch electrical switches, the phone or anything that sparks, to ventilate by opening doors and windows and to close the main gas tap. Then leave the home and call your gas distributor's emergency number from the street.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
- Higheditorial warning
Do not chain resets with A02: it is a temperature safety cut. If it returns, leave the boiler on OFF and wait for the technical service.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
Symptoms and causes
Probable causes · in order
- Real overheating of the waterPossible
The thermostat did its job. It fits if A02 appears after heating for a while and pressure was low or there was air.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
- Limit thermostat or its wiringPossible
If A02 appears with the boiler cold or right at start up, it points to the thermostat or its connection, not to temperature.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
- Overdue circuit maintenanceLess common
Beretta's maintenance list includes checking pressure and that the heat exchanger is clean; a neglected circuit carries heat away less well.
Evidence: Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
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
Beretta Ciao Green 25 y 29 C.S.I., manual de instalación y uso
Beretta · 2015 · manual
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