- Boilers
- Gas boiler
F96
Cointra F96 on a gas boiler: unstable flame after ignition
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Cointra F96 means an unstable flame or unstable flame signal after ignition. Check there is no smell of gas or fumes and that the gas tap is open, then wait about 3 minutes: Cointra says the error clears by itself.
Safety first
Stop and check this first
- If you smell gas, do not reset or press anything electrical: open windows, close the gas tap if it is within reach, leave the home and call your gas distributor's emergency number from the street. Cointra says to switch a faulty boiler off and have it repaired only by an authorised technician.
- Cointra warns of a risk of asphyxia from escaping flue gases if the boiler runs with the siphon empty or the flue circuit is not sealed. Headache, dizziness or nausea can mean carbon monoxide: switch the boiler off, ventilate, leave and get help. Keep a CO alarm nearby.
Safe checks you can perform
- Gas or flue gas smell near the boiler
- Gas tap before the boiler
- Wait about 3 minutes
- Flue terminal and condensate pipe in view
- Gas, flue, siphon and electrode by the technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Gas supply pressure
- Do not attempt this professional task: Flue ducts and siphon
- Do not attempt this professional task: Electrode and CO2 check
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.
Gas supply pressure
What they doThe technician measures the gas pressure reaching the boiler with a manometer, as Cointra asks for F96 and the combustion errors.
They must show youthe manometer reading.
In writingthe value measured against the manufacturer's specification.
Flue ducts and siphon
What they doChecks that the flue ducts and condensate siphon are not blocked and that the siphon holds water.
They must show youthe terminal and siphon checked.
In writingwhat was blocked and what was cleaned.
Electrode and CO2 check
What they doChecks the electrode position and condition and, if it is replaced, runs the full manual calibration and measures CO2 with an analyser against the Cointra table.
They must show youthe analyser printout.
In writingthe CO2 values measured against the manufacturer's specification and the part replaced.
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.
Gas or flue gas smell near the boiler
- Who:
- you.
- How:
- walk up without pressing switches or turning lights on and notice whether there is a smell of gas or combustion fumes.
- Result that matters:
- whether there is a smell or not.
- If there is a smell:
- do not touch the boiler and follow the gas warning on this page.
- If there is no smell:
- go on to check the gas tap.
- Evidence to keep:
- the time and what you noticed.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
Gas tap before the boiler
- Who:
- you.
- How:
- find the gas tap located before the boiler and check whether the lever is fully open, without taking anything apart.
- Result that matters:
- whether it is open, half open or closed.
- If it was closed or half open:
- open it fully and watch whether F96 clears.
- If it was open:
- go on to wait for the error to clear.
- Evidence to keep:
- a photo of the tap position.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
Wait about 3 minutes
- Who:
- you.
- How:
- do not press anything and let about 3 minutes pass, the time Cointra gives for F96 to clear by itself.
- Result that matters:
- whether the boiler works again and how often F96 comes back.
- If it clears and does not return:
- note the day and time in case the technician needs it.
- If it returns often:
- go on to look at the flue and condensate and call the technician.
- Evidence to keep:
- the time of each appearance of the code.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
Flue terminal and condensate pipe in view
- Who:
- you.
- How:
- from the ground or a window look at the flue outlet, and under the boiler at the flexible condensate pipe, without opening the casing.
- Result that matters:
- whether the terminal is covered or damaged and whether the pipe is kinked, loose or frozen.
- If something looks wrong:
- take a photo and tell the technician; do not handle it yourself.
- If everything looks fine:
- the gas or the electrode become more likely.
- Evidence to keep:
- photos of the terminal and the pipe.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
Gas, flue, siphon and electrode by the technician
- Who:
- authorised gas technician.
- How:
- measures the gas supply pressure, checks the flue ducts and siphon, checks the electrode position and condition and checks CO2 with an analyser.
- Result that matters:
- which part makes the flame unstable.
- If the gas pressure or the flue is at fault:
- the installation is put right before the boiler is touched.
- If the electrode is at fault:
- it is repositioned or replaced and the calibration Cointra requires is done.
- Evidence to keep:
- a report with gas pressure, CO2 measured and parts handled.
Cointra leaves repairs and part replacement to authorised technicians. The electrode, internal siphon and gas valve are inside the casing.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
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
- Cointra
- Product type
- Gas boiler
Known code variants
- BlueHelix HiTech F96
- BlueHelix HiTech RRT F96
- Cointra F 96
- Error F96 Cointra
- F 96
- Ferroli F96
- Superlative Supra F96
- Supra F96
What it means
In the Superlative Supra C fault table, F96 is a specific combustion error: the flame or its signal becomes unstable after ignition. The letter F is a transient lockout that clears by itself and Cointra says the error resets after about 3 minutes. The remedy it gives is to check the gas supply, the flue ducts and the condensate drain, and the position and condition of the electrode. The code does not say which of those parts is at fault.
Warnings and stop conditions
- Criticaleditorial warning
If you smell gas, do not reset or press anything electrical: open windows, close the gas tap if it is within reach, leave the home and call your gas distributor's emergency number from the street. Cointra says to switch a faulty boiler off and have it repaired only by an authorised technician.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
- Criticaleditorial warning
Cointra warns of a risk of asphyxia from escaping flue gases if the boiler runs with the siphon empty or the flue circuit is not sealed. Headache, dizziness or nausea can mean carbon monoxide: switch the boiler off, ventilate, leave and get help. Keep a CO alarm nearby.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
Symptoms and causes
Probable causes · in order
- Irregular gas supplyPossible
Cointra says to check the gas supply. It fits if the tap is not fully open or other gas appliances in the home also misbehave.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
- Blocked flue ductsPossible
Cointra says to check the flue ducts. It fits if the outside terminal is covered or damaged, or in strong wind.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
- Blocked condensate drainPossible
Cointra lists the condensate drain. It fits if the condensate pipe is kinked, frozen or never drips.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
- Electrode out of position or dirtyPossible
Cointra says to check the electrode position and condition. It comes into play when gas, flue and condensate are fine and F96 repeats.
Evidence: Cointra SUPERLATIVE SUPRA C, instrucciones de uso, instalación y mantenimiento (cod. 3541V210)
Virtual technician
Does F96 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
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