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Ideal boiler fault codes
Common Ideal codes for Logic, Logic+, Logic Max, Vogue and i-mini boilers, what they mean and what to do.
Ideal boilers show F codes for faults the boiler can recover from, and L codes for lockouts that need a reset. The reset is usually a button or a dial turned to the reset position.
| Code | What it means | What to do |
|---|---|---|
| F1 | Low water pressure. | Top up to about 1 to 1.5 bar with the filling loop. Book a repair if it keeps dropping. You may be able to fix this |
| F2 | Flame lost. | Check your gas supply and meter credit, then reset. Book a repair if it repeats. Engineer needed if it returns |
| L2 | Ignition lockout. Very often a frozen or blocked condensate pipe in winter. | Thaw the condensate pipe with warm (not boiling) water, then reset. If it is not frozen, book a repair. Engineer needed if it returns |
| F3 | Fan fault. | Needs an engineer to check the fan and flue. Engineer needed if it returns |
| F4 | Flow thermistor (temperature sensor) fault. | Book a repair visit. Engineer needed if it returns |
| F5 | Return thermistor fault. | Book a repair visit. Engineer needed if it returns |
| L1 | Overheat, or no water flowing through the boiler. | Check the pressure and that radiator valves are open. If it returns, the pump or a blockage needs checking. Engineer needed if it returns |
| L6 | Flame detection fault. | Do not keep resetting. An engineer needs to check the flame sensor and gas valve. Engineer needed if it returns |
| F9 | Circuit board not configured. | Usually after a board change. An engineer needs to set it up. Engineer needed if it returns |
Codes and their meanings can vary between models and software versions, so check your boiler’s manual too. Never open the boiler casing yourself.
How to top up the pressure
Low pressure is the most common cause of a Ideal lockout. With the boiler cold, open the filling loop valves slowly until the gauge reads about 1 to 1.5 bar, then close them fully. Your manual shows where the filling loop is on your model. Read our full guide.
When to book an engineer
- The same code comes back after one reset
- The pressure keeps dropping after you top it up
- You see a false flame, flue or gas valve code
- There is water leaking from the boiler
Ideal questions
What does F1 mean on a Ideal boiler?
Low water pressure. Top up to about 1 to 1.5 bar with the filling loop. Book a repair if it keeps dropping.
How do I reset a Ideal boiler?
Most models have a reset button or a dial position marked reset. Press or turn it once, and wait a few minutes for the boiler to try again. Check your manual for your model. If the code returns, do not keep resetting it.
Do you repair Ideal boilers?
Yes. Our Gas Safe engineers repair Ideal boilers across South London. A repair visit is £90 including the first hour.
Other makes: Vaillant, Worcester Bosch, Baxi.