- Boilers
- Gas boiler
96
Immergas 96 on a gas boiler: air intake or flue ducts blocked
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Immergas 96 means the boiler has detected a blockage in the air intake or flue ducts. Check from outside that the terminal is not covered, do not dismantle it and, if the code stays, 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.
- If you get a headache, dizziness or nausea while the boiler runs, there may be carbon monoxide: switch it off, ventilate, leave the home and call the emergency services. A CO alarm near the boiler warns you before symptoms start.
- Do not dismantle or tamper with the air intake and flue ducts: Immergas forbids this to the user. If there was work near them, qualified staff must check they work properly before you keep using the boiler.
Safe checks you can perform
- Terminal seen from outside
- Work near the ducts
- Whether the code clears by itself
- Duct test and combustion check by the technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Air intake and flue duct test
- Do not attempt this professional task: Flue gas recirculation
- Do not attempt this professional task: Combustion 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.
Air intake and flue duct test
What they doWith the trap full, the sealed chamber closed and all ducts fitted, the technician activates the duct test, measures the pressure difference between the two test points and compares it with the Immergas table and with the value recorded at the first check.
They must show youthe pressure difference measured.
In writingthe measured value, the first check value and the F0 setting.
Flue gas recirculation
What they doThrough the analysis points, with the boiler at maximum output, the technician checks that the CO2 measured in the intake air is below 10% of that measured in the flue gases, as Immergas asks.
They must show youboth CO2 values.
In writingthe ratio measured and the correction if it fails.
Combustion analysis
What they doUsing the chimney sweep function, the technician measures CO2 at the three reference outputs and CO. Immergas sets a maximum CO below 700 ppm at the annual check and below 500 ppm after a repair.
They must show youthe analyser printout.
In writingthe CO2 and CO values measured against the manufacturer'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.
Terminal seen from outside
- Who:
- you.
- How:
- from the street, the yard or the ground, without climbing ladders or onto the roof, look at the air intake and flue terminal. Immergas asks you to check it is not blocked.
- Result that matters:
- whether something is covering the intake or the outlet.
- If it is covered:
- do not dismantle or tamper with the ducts; tell the technician.
- If it is clear:
- the blockage may be inside; go to the next check.
- Evidence to keep:
- a photo of the terminal.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Work near the ducts
- Who:
- you.
- How:
- think back to whether there was building work, scaffolding or other work near the ducts or the terminal before E96 appeared.
- Result that matters:
- whether someone may have touched or covered the ducts.
- If there was:
- Immergas asks for qualified staff to check the ducts work properly after such work.
- If there was not:
- tell the technician anyway; it helps target the check.
- Evidence to keep:
- a note of the dates of the work.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Whether the code clears by itself
- Who:
- you.
- How:
- do not press Reset; watch whether E96 clears and the boiler runs again. Immergas says it restarts without a reset if normal conditions return.
- Result that matters:
- whether it is one-off or repeats.
- If it clears and does not return:
- note the date, time and the weather.
- If it repeats or stays on:
- call the technician; the ducts are checked with instruments.
- Evidence to keep:
- a photo of the display and a note of each occurrence.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Duct test and combustion check by the technician
- Who:
- technician from an authorised company.
- How:
- runs the air intake and flue duct test, checks that flue gases are not recirculating and analyses combustion.
- Result that matters:
- where the blockage or pressure loss is.
- If the test gives values different from the table:
- the blockage or fitting fault is found and corrected.
- If combustion is out of specification:
- the boiler is not used again until it is corrected.
- Evidence to keep:
- a job sheet with the values measured.
Immergas forbids the user to dismantle or tamper with the air intake and flue ducts. The test and combustion analysis are done by an authorised company.
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
- E96
- Error 96 Immergas
- Immergas E96
- Victrix 96
- Victrix E96
What it means
On the Victrix Zeus 25/32, E96 means blocked air intake or flue ducts: the appliance detects an obstruction in those ducts. If normal conditions return, it restarts without a reset. Immergas explains that its duct test reveals problems from excessive pressure losses or obstructions. The code does not say where the problem is: at the outside terminal, inside the air or flue duct, or in the way the ducts are fitted; the technician checks.
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)
- Criticaleditorial warning
If you get a headache, dizziness or nausea while the boiler runs, there may be carbon monoxide: switch it off, ventilate, leave the home and call the emergency services. A CO alarm near the boiler warns you before symptoms start.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Highsource verified
Do not dismantle or tamper with the air intake and flue ducts: Immergas forbids this to the user. If there was work near them, qualified staff must check they work properly before you keep using the boiler.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Symptoms and causes
Probable causes · in order
- Outside terminal coveredPossible
Fits if from outside you can see something covering the terminal. Immergas says not to obstruct the intake and exhaust terminal, not even temporarily.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Blockage inside the ductsPossible
Fits if the terminal is clear and E96 repeats. Only the duct test Immergas describes, with the boiler in test mode, can detect it.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- How the ducts are fittedPossible
Fits if E96 appeared after building work or changes to the ducts. Immergas asks for the elements to be properly joined so they cannot come loose; the test reveals excessive pressure losses.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Virtual technician
Does 96 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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