Overview
The Ideal F2 error code means the boiler has detected flame loss or an ignition lockout. In plain terms the boiler tried to light or stay lit but the flame went out or could not be confirmed, so the control system has locked the appliance out as a safety measure. The lockout prevents the boiler from running until the underlying issue is found and corrected. Common causes include interruption or low mains gas pressure, a stuck or faulty gas valve, a faulty fan or flue-venting problem (blocked or damaged flue), or internal electrical faults such as loose wiring or a PCB issue. Severity is moderate to high because the fault involves gas and combustion safety; the lockout itself is a protective action, but the root causes can be hazardous if mishandled. Some simple checks and a single reset can be performed by a homeowner, but diagnosing and repairing gas components, the fan, flue or PCB must be left to a qualified Gas Safe registered engineer.
Troubleshooting Steps
Safety first
- If you smell gas: turn off the gas at the meter or isolation valve if you can do so safely, do not operate electrical switches or use phones inside the property, open windows/doors, evacuate everyone from the building and call the national gas emergency number immediately. Do not attempt any internal repairs.
- If you do not smell gas, work calmly and only do the safe, non-invasive checks listed below. Do not open the boiler casing or attempt to work on gas or electrical components yourself.
Initial checks any homeowner can do (safe, non-invasive)
1. Note the fault: write down ‘F2’ and what the boiler was doing (trying to light, running then cut out, intermittent). Note date/time and whether it repeats. This helps the engineer.
2. Check other gas appliances: light a gas hob burner or check a gas fire. If no other gas appliance works, the problem is likely a supply issue and you should contact your gas supplier. If other appliances work, the issue is local to the boiler.
3. Check the gas meter and any prepay meter credit: ensure the service lever at the meter is in the ON position and, for prepay meters, that you have credit.
4. Check the boiler’s power supply and fuse spur: ensure the boiler is powered and any external switches/fuses are on.
5. Visually inspect the external flue terminal from ground level only: look for obvious blockages (leaves, bird, debris) or damage. Do not climb on ladders or roofs — if the flue is high or inaccessible, do not attempt to clear it yourself.
6. If the boiler has an external condensate pipe and it is very cold, check for freezing. A frozen condensate can cause lockouts; you can gently thaw a frozen condensate pipe with warm water (not boiling) or a warm cloth. If you are unsure, do not attempt and call an engineer.
Safe reset procedure (one attempt)
1. Note the error and any behaviour first. Try a single reset following the manufacturer’s method: use the boiler reset button or turn the mode control knob off, wait 10–20 seconds, then restore it. Alternatively turn off at the boiler spur, wait 10 seconds and turn back on. Only attempt one reset; multiple repeated resets can mask a persistent fault and are discouraged.
2. After reset, observe whether the boiler completes its ignition sequence and runs normally. If it restarts and runs, monitor for recurrence. If the F2 returns immediately or within a short time, stop further resets and proceed to call an engineer.
What a Gas Safe engineer will check (do not attempt yourself)
- Confirm mains gas pressure at the meter and at the appliance and check for interruptions or regulator issues.
- Inspect the gas valve for sticking or failure and test associated wiring and solenoids.
- Inspect the fan and air/gas flow system and run diagnostic tests on the fan speed and safety interlocks.
- Inspect the flue and flue guard, remove and clear any blockages safely (including rooftop/vertical flues), and check for damage or improper termination.
- Check PCB wiring, flame detection circuit, and ignition components such as the spark/ionisation probe.
When to call a professional
- If reset does not clear the fault, if the F2 error recurs, if you found no external gas supply to other appliances, if you see flue damage or inaccessible blockage, or if you smell gas, call a Gas Safe registered engineer immediately. Do not attempt to access or repair internal gas components, the gas valve, fan, or PCB yourself.
Information to give the engineer
- Boiler make/model and serial if available, the exact error code (F2), when it occurs (during ignition, after running a while, intermittent), what you checked (other gas appliances, meter, flue visible blockage, reset attempt), and date of last service. This speeds diagnosis.
Final notes
- The F2 lockout is a safety feature; while a single reset and basic external checks are reasonable for a homeowner, the underlying causes normally require a qualified Gas Safe engineer to safely diagnose and repair. Arrange a professional service if the fault persists or you are unsure.
Helpful Resources
Boiler Manual
Download the official PDF manual for the Ideal Ideal Boiler.