- Boilers
- Gas boiler
94
Immergas 94 on a gas boiler: combustion control fault
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Immergas 94 means a combustion control problem caused by low gas pressure, flue gas recirculation, the gas valve or the board. It only shows in the information menu. Check the gas tap is open and call the technician.
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.
Safe checks you can perform
- Code in the information menu list
- Gas tap and other gas appliances
- Flue terminal seen from outside
- Gas, ducts and valve check by the technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Dynamic gas pressure
- Do not attempt this professional task: Flue gas recirculation
- Do not attempt this professional task: Combustion analysis
- Do not attempt this professional task: Gas valve and board
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.
Dynamic gas pressure
What they doThe technician measures the dynamic gas supply pressure with the boiler running. Immergas asks for it to comply with EN 437, because insufficient pressure affects output, and says the appliance must not be started if pressures are higher than needed.
They must show youthe pressure measured against the manufacturer's specification.
In writingthe value measured and, if it fails, who was notified.
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.
Gas valve and board
What they doIf gas and ducts are in specification, the technician checks the gas valve, its connection and the electronic board, and reads the last five faults at d 0.8 for other gas valve codes.
They must show youthe checks made and the fault list.
In writingthe part replaced, its reference and 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.
Code in the information menu list
- Who:
- you.
- How:
- E94 does not show on the normal display; Immergas states it can only be seen in the fault list of the information menu. Press the information button for at least 1 second and step to d 0.8, which shows the last five faults.
- Result that matters:
- whether E94 is on the list and how often.
- If it appears several times:
- tell the technician; if it appears with E84, low gas supply pressure has also been detected.
- If it appears once:
- note the date and time and check the list again in a few days.
- Evidence to keep:
- a photo of the fault list.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Gas tap and other gas appliances
- Who:
- you.
- How:
- check under the boiler that the gas tap is fully open and, if you have another gas appliance, whether it works normally.
- Result that matters:
- whether gas is arriving normally.
- If the tap was half open:
- open it fully and tell the technician.
- If another gas appliance also works badly:
- contact your gas distributor; a supply pressure problem fits.
- Evidence to keep:
- a note of the tap position and how the other appliances work.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Flue 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 covers the intake or the outlet.
- If it is covered:
- do not dismantle or tamper with the ducts; tell the technician.
- If it is clear:
- rule out a visible blockage; the technician checks whether flue gases are drawn back into the intake.
- Evidence to keep:
- a photo of the terminal.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Gas, ducts and valve check by the technician
- Who:
- technician from an authorised company.
- How:
- measures the dynamic gas pressure, checks for flue gas recirculation, analyses combustion and checks the gas valve and the board.
- Result that matters:
- which of the four Immergas causes applies.
- If the gas or ducts are out of specification:
- they are corrected before the boiler is used further.
- If they are in specification and E94 continues:
- the gas valve and board are checked.
- Evidence to keep:
- a job sheet with the values measured and parts replaced.
Gas, gas valve, board and ducts are work for an authorised company; Immergas 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
- E94
- E:94
- Error 94 Immergas
- Fujitsu 94
- Fujitsu E94
- Immergas E94
- Victrix 94
- Victrix E94
What it means
In the Victrix Zeus 25/32 table, E94 is a combustion fault: a problem is detected in combustion control that may be caused by low gas pressure, flue gas recirculation, the gas valve or a faulty electronic board. If normal conditions return, the appliance restarts without a reset, and the fault only shows in the fault list of the information menu. If it persists, Immergas says to call an authorised company. The code does not say which of the four causes applies.
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)
Symptoms and causes
Probable causes · in order
- Low gas pressurePossible
Fits if the tap is not fully open or other gas appliances work badly. Immergas lists it as a cause; the technician measures the dynamic supply pressure.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Flue gas recirculationPossible
Fits if gas arrives normally and flue gases are drawn back into the air intake. Immergas lists it as a cause; it is confirmed by measuring CO2 in the intake air.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Faulty gas valve or electronic boardPossible
Fits if gas and ducts are in specification and E94 repeats. Immergas lists a faulty gas valve or board; only the technician can check them.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Virtual technician
Does 94 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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