Ideal F2 fault codewhat it means and how to fix it
The flame was lost during operation. Ideal direct you to check the gas supply first, and that is genuinely the right order.
Take care
What F2 means
Ideal split their codes into two families and the prefix tells you how serious the appliance considers the fault. An L code is a lockout that will not clear until somebody resets it. An F code is an operational fault the appliance may recover from by itself. F2 is flame loss: the burner lit and then the flame signal disappeared during the cycle. The fact that Ideal classify this as F rather than L is informative — the appliance expects to be able to retry.
What separates F2 from the L2 ignition lockout is that on an F2 combustion definitely started, so the ignition electrode worked and gas reached the burner. Ideal's own user guide sends you straight to the gas supply: check other appliances in the house, then the meter and any prepayment credit. That order is right, because an intermittent or under-pressure supply is the most common reason a flame that lit does not stay lit.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Gas supply interrupted or inadequate | Ideal list this first. A supply that sags under full rate will light the burner and then fail to sustain it, which looks baffling until you test it against another appliance. | Common |
| Condensate backing up | A partly blocked trap or a frozen external run floods the chamber shortly after firing. Recognisable because the run time before failure is consistent. | Common |
| Flame sensing electrode marginal | Reads adequately from cold and drops below threshold once the chamber heats. Characteristic of an electrode near the end of its life. | Occasional |
| Flue blockage or recirculation | Combustion products drawn back into the intake once the appliance warms up, degrading combustion until the flame fails. | Occasional |
What to try yourself
Check other gas appliances in the property are working. Ideal make this step one, and it separates a supply problem from a boiler problem in under a minute.
If nothing else runs on gas, check the supply is on at the meter and that any prepayment meter has credit.
Time how long the appliance runs before F2 appears, over two or three attempts. A consistent interval suggests condensate; an unpredictable one suggests supply.
In cold weather, check the external condensate pipe for ice and thaw it with hand-hot water if you find any.
Never use boiling water or a heat gun on a condensate pipe — cold plastic splits easily.If the appliance is still under Ideal warranty, contact Ideal directly rather than an independent engineer, or you may invalidate the cover.
Get a Gas Safe registered engineer to look at your Ideal F2
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
What it costs to fix
Typical repair cost
£0–£420
Time on site
25 minutes
Free if the gas supply or a frozen condensate pipe is the cause. An electrode is £110 to £190 fitted. Gas supply pipework corrections range from £200 to over £600.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Parts you may need
We may earn a commission if you buy a part through one of these links. It does not change what you pay, and it does not affect which parts we list.
Ideal Logic ignition electrode
175565£18–£42Authorised Ideal parts distributor
Price checked 28 September 2026
Condensate trap and siphon
COND-TRAP£15–£38Plumbing merchant
Price checked 28 September 2026
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Ideal fault codes
- L2Stop — call an engineerThe boiler failed to detect a flame during ignition and has locked out on the gas valve. Do not keep resetting it.Related: ignition and gas supply
- LCUsually simple to fixYou have reset the appliance five times in fifteen minutes. This is not a fault in itself — it is the boiler asking you to stop.Related: ignition and gas supply
- L FStop — call an engineerAn Isar, Icos, Mexico HE or Esprit has made three attempts to light and locked out; the LED window flashes L then F. Ideal permit one reset and a gas supply check, then an engineer.Related: ignition and gas supply
- L6Stop — call an engineerA flame is being detected when there should not be one. Turn the appliance off and call a Gas Safe engineer rather than resetting it.Related: ignition and gas supply
- F16Stop — call an engineerThe board has detected a fault in the gas valve or its wiring. Nothing here is for a householder to try; Ideal's checks cover the valve's supply and coil and end with replacing it.Related: ignition and gas supply
- F10Get it checkedThe spark generator on a Logic Combi2 — the unit that makes the ignition spark — has failed a self-check. Ideal's instruction is to check its wiring and, if that is sound, replace it.Related: ignition and gas supply
Own an Ideal boiler? Save it and its codes come first next time.
Related guides
Common questions about Ideal F2
What is the difference between F2 and L2 on an Ideal?
L2 is an ignition lockout — the burner never lit and the appliance has latched off. F2 is flame loss — it did light and then went out. The L prefix means it will not restart without a manual reset; the F prefix means the appliance may retry on its own.
Does the warranty matter here?
It does. Ideal warranties are long and they require Ideal or an approved engineer to attend. Their own documentation says to contact Ideal if under warranty and a Gas Safe engineer if outside it. Check your paperwork before calling anyone.
Will F2 clear by itself?
Often, yes. The F prefix marks a fault the boiler will try to recover from, so once the supply steadies the burner relights without you touching it. If the same failure keeps repeating you may find the display has moved to L2, the ignition lockout, and that one does need the reset button.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
- Manufacturer support portal
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.