- Boilers
- Gas boiler
02
Immergas 02 on a gas boiler: overheat safety thermostat lockout
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Immergas 02 means the safety thermostat has locked the boiler out after internal overheating. Check the gauge reads 1 to 1.2 bar when cold, press Reset once and, if it returns, call the authorised technical service.
Safety first
Stop and check this first
- If you smell gas: Immergas says to close the meter or main gas tap and, if you can, the boiler's gas tap, open doors and windows, use no naked flames, do not smoke and do not touch switches, sockets, doorbells or phones. Leave the home and call your gas distributor's emergency number from the street.
- Do not chain Resets with E02: after 5 in a row the boiler shows E08 and accepts no more Resets for an hour. If the lockout persists, Immergas says to call the Authorised Technical Assistance Centre.
- If you smell burning or see smoke coming from the boiler: Immergas says to switch it off, disconnect the power supply, close the main gas tap, open the windows and call an authorised company.
Safe checks you can perform
- Pressure gauge reading when cold
- Radiator valves
- One Reset
- Pump and safety thermostat check by the technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Circulation pump
- Do not attempt this professional task: Safety thermostat and pressure switch
- Do not attempt this professional task: Pressure, expansion vessel and fault history
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.
Circulation pump
What they doThe technician checks that the pump runs and, if it is stuck after long inactivity, frees the motor shaft by hand with the screw in the centre of the head, taking care not to damage it, as Immergas describes.
They must show youthe pump running and the boiler heating without a lockout.
In writingwhether it was stuck or faulty and what was done.
Safety thermostat and pressure switch
What they doThe technician visually checks that the temperature safety thermostat and the system pressure switch have not been tampered with or short-circuited, as Immergas asks at the annual maintenance.
They must show youthe condition and connection of both devices.
In writingwhat was checked and any part replaced, with its reference and reason.
Pressure, expansion vessel and fault history
What they doWith the pressure brought to zero, the technician checks that the expansion vessel charge is 1.0 bar and that static pressure ends up at 1 to 1.2 bar. They also read the last five faults at d 0.8.
They must show youthe fault list and the measured vessel charge.
In writingthe values measured and the cause found.
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 when cold
- Who:
- you.
- How:
- with the system cold, look at the boiler's pressure gauge needle. Immergas asks for 1 to 1.2 bar. If it is below 1 bar, first check that the mains water is at least 2.5 bar; if so, top up slowly with the filling tap underneath and close it when done.
- Result that matters:
- whether the boiler is short of water.
- If it was below 1 bar:
- lack of water fits; note how much you topped up.
- If it was 1 to 1.2 bar:
- rule out lack of water and go to the next check.
- Evidence to keep:
- a photo of the gauge before and after.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Radiator valves
- Who:
- you.
- How:
- go round the home and check whether the radiator valves are open. Immergas asks for a check that they are not all closed.
- Result that matters:
- whether the water has somewhere to circulate.
- If nearly all were closed:
- open several; low circulation fits.
- If they were open:
- rule this cause out; the pump or the sensor remain, which the technician checks.
- Evidence to keep:
- a note of which valves were closed.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
One Reset
- Who:
- you.
- How:
- press the Reset button once, as Immergas states for E02.
- Result that matters:
- whether the boiler runs again and the code stays away.
- If it runs and does not return:
- note the date and time.
- If E02 returns:
- stop; Immergas says to call an authorised company, for example the Authorised Technical Assistance Centre. After 5 Resets in a row the boiler shows E08 and blocks Reset for an hour.
- Evidence to keep:
- a photo of the display with the code and a note of each Reset.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Pump and safety thermostat check by the technician
- Who:
- technician from an authorised company.
- How:
- checks that the pump runs, that the safety thermostat has not been tampered with, and the pressure and expansion vessel.
- Result that matters:
- why the boiler overheats.
- If the pump is stuck or faulty:
- it is freed or repaired before the boiler is used again.
- If the thermostat or pressure switch has been tampered with or bridged:
- it is corrected.
- Evidence to keep:
- a job sheet with what was found and repaired.
Immergas reserves maintenance and repairs for an authorised company and tells the user not to open or tamper with the appliance.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
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
- Immergas
- Product type
- Gas boiler
Known code variants
- E02
- Error 02 Immergas
- Immergas E02
- Victrix 02
- Victrix E02
What it means
In the Victrix Zeus 25/32 table, E02 is the safety thermostat (overheat) lockout: during normal operation a fault causes excessive internal overheating and the appliance locks out. In its troubleshooting table, Immergas links frequent trips of this thermostat to lack of water in the appliance, low water circulation in the system or a blocked circulation pump. The code does not say which one happened; the pump and the thermostat are checked by the technician.
Warnings and stop conditions
- Criticaleditorial warning
If you smell gas: Immergas says to close the meter or main gas tap and, if you can, the boiler's gas tap, open doors and windows, use no naked flames, do not smoke and do not touch switches, sockets, doorbells or phones. Leave the home and call your gas distributor's emergency number from the street.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Highsource verified
Do not chain Resets with E02: after 5 in a row the boiler shows E08 and accepts no more Resets for an hour. If the lockout persists, Immergas says to call the Authorised Technical Assistance Centre.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Highsource verified
If you smell burning or see smoke coming from the boiler: Immergas says to switch it off, disconnect the power supply, close the main gas tap, open the windows and call an authorised company.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Symptoms and causes
Probable causes · in order
- Lack of water in the appliancePossible
Fits if the gauge reads below 1 bar when cold. Immergas lists lack of water as a cause of frequent trips of the overheat safety thermostat.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Low circulation in the systemPossible
Fits if nearly all radiator valves were closed. Immergas asks for a check that they are not all closed when this thermostat trips often.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Blocked circulation pumpPossible
Fits if the pressure and radiators are fine, especially after a long time without using the boiler. Immergas warns that after long inactivity the pump may stick; freeing it is technician work.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Virtual technician
Does 02 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
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