Ideal Boiler F2 Fault Code: Causes & Fixes

The Ideal boiler F2 fault code means the boiler has tried to light the burner but has failed to detect a flame after several attempts. In simple terms, the boiler is saying “I’ve opened the gas valve and sparked the igniter, but I can’t prove the gas is actually burning safely”. This is a safety lockout to prevent unburnt gas building up in the property.

In this guide, I’ll explain exactly what the Ideal boiler F2 fault code means, the most common reasons it appears, and step-by-step fixes for each cause.

What Causes the Ideal F2 Fault Code?

There are several proven reasons why Ideal boilers show the F2 error. Here are the most frequent culprits we see across the UK:

1. Frozen or Blocked Condensate Pipe

The condensate pipe (usually a white or grey plastic pipe that runs from the boiler to an outside drain) can freeze in cold weather, or become blocked with sludge and debris.

How to fix a frozen/blocked condensate pipe yourself

• Locate the condensate pipe outside the property (it exits the boiler and goes through the wall).
• If it’s frozen, gently pour warm (not boiling) water over the pipe or use a hot water bottle wrapped around it until it thaws.
• Once thawed, reset the boiler by holding the reset button for 3–5 seconds.
• To prevent it happening again, insulate the pipe with foam lagging (available at any DIY store for under £5).

2. Faulty Flame Detection Electrode (Ionisation Probe)

The flame detection electrode is a small metal probe that sits in the flame and tells the PCB (main circuit board) that the burner is lit. Over time it can get covered in carbon or become misaligned.

How to fix a faulty flame detection electrode

This is a job for a Gas Safe registered engineer only. They will clean the probe with emery cloth, check its gap (usually 3–4 mm from the burner), and replace it if damaged. A new probe costs around £15–£25 + labour.

3. Broken or Dirty Igniter / Spark Electrode

The spark electrode creates the spark to light the gas. If it’s cracked, covered in soot, or the lead is damaged, no spark = no flame = F2 fault.

How to fix a faulty igniter

Again, only a Gas Safe engineer can safely remove the burner assembly, clean or replace the electrode and leads. Replacement electrodes are inexpensive (around £20–£30).

4. Gas Valve Problems or Low Gas Pressure

The gas valve controls the flow of gas to the burner. If the stepper motor inside the valve fails or there is low gas supply pressure, the boiler won’t light properly.

How to fix gas valve or low pressure issues

• First check the obvious: is your gas meter prepaid and in credit? Is the emergency control valve by the meter fully open?
• If yes, then the gas valve or gas supply needs testing with a manometer – strictly a Gas Safe job. A new gas valve for an Ideal Logic typically costs £180–£250 fitted.

5. Printed Circuit Board (PCB) Fault

The PCB is the “brain” of the boiler. If it cannot process the flame signal correctly, it will lock out with F2.

How to fix a PCB fault

PCBs on Ideal boilers are reliable, but they do occasionally fail. A replacement PCB for a Logic or Logic+ costs between £220–£320 including labour and programming.

6. Blocked or Dirty Burner

Years of dust, soot and general debris can clog the burner, preventing proper combustion.

How to fix a blocked burner

The burner must be removed and cleaned thoroughly – only a qualified engineer can do this safely.

How to Reset an Ideal Boiler Showing F2

After you’ve addressed the possible cause (e.g., thawed the condensate pipe), reset the boiler:

1. Press and hold the reset button (usually marked with a flame and spanner icon) for 3–5 seconds.
2. The display should clear and attempt to fire again.
3. If the F2 fault returns immediately or after a few minutes, stop resetting and call a Gas Safe engineer.

How to Prevent the Ideal F2 Fault Code in the Future

• Lag the condensate pipe properly with waterproof insulation.
• Book an annual boiler service – a clean burner and electrodes dramatically reduce F2 faults.
• Fit a magnetic system filter (e.g., MagnaClean or Fernox TF1) to keep the system clean.
• Consider a weather compensation kit or outdoor sensor – these help the boiler run more gently and reduce wear on ignition components.
• Keep an eye on gas credit if you’re on a prepayment meter.

When You Absolutely MUST Call a Gas Safe Engineer

You must call a Gas Safe registered engineer immediately if:

• The F2 fault keeps returning after resetting twice.
• You can smell gas at any point.
• You’re unsure about the condensate pipe or anything inside the boiler casing.
• Your boiler is still under the manufacturer’s warranty (usually 7–12 years on Ideal Logic/Vogue models) – DIY attempts can invalidate it.

Working on the combustion side of any gas boiler without Gas Safe registration is illegal in the UK and extremely dangerous.

FAQs 

Will my Ideal boiler still provide hot water when it’s showing F2?

No – the F2 fault locks out both heating and hot water because the boiler cannot safely detect a flame.

Is the F2 fault covered under my Ideal warranty?

Yes, provided the boiler has been serviced annually by a Gas Safe engineer and the fault is not caused by a frozen condensate pipe (which is classed as an external issue).

How long can I safely leave an F2 fault before getting an engineer?

If you have no heating or hot water in winter, treat it as urgent. A competent engineer can normally attend within 24–48 hours, and many offer same-day service for lockouts.

Are newer Ideal Logic Max models less likely to get F2 faults?

The Logic Max range has an improved ignition system and aluminium heat exchanger, which has slightly reduced F2 occurrences, but frozen condensate pipes still affect every brand equally.

Can low water pressure cause an F2 fault on Ideal boilers?

No – low pressure normally triggers an F1 or L1 fault. F2 is specifically related to flame detection and ignition problems.