Ideal boiler fault codes
Ideal codes come in two letters and the letter is the whole of the grammar. L is a lockout: the boiler has stopped and stays stopped until somebody presses Restart. F is the same class of fault in a state the appliance can recover from on its own, or a condition it is reporting rather than a stoppage. Ideal's own tables show the pairing by printing some faults in both columns — F4 and L4 are one flow thermistor, F5 and L5 one return thermistor, F9 and L9 one unconfigured board, and on the 2012–2015 Logic ES boards F2 and L2 are one flame loss. So an L is not a worse fault than an F; it is the same fault that has given up trying. The pairing holds only where Ideal print both codes: F1 is low pressure and L1 is an overheat, and those are different faults that happen to share a digit. The older LED ranges — Isar, Icos, Mexico HE, Esprit, Elise — use H in place of F, and Ideal's Esprit guide states the rule plainly: codes beginning with H are temporary and reset when the condition clears, codes beginning with L are permanent and cause a lockout. Where a number means something different from one range to the next — L5, L8, L9 and L3 all do — the code page names the ranges and tells you how to recognise which one you are standing in front of.
Where the code shows on a Ideal
Five display generations, and the shape of the code tells you which you have. Isar HE, Icos HE, Mexico HE, Esprit and Elise have a single LED window that alternates between a letter and a character — L then F, H then 1 — so the code is read as a pair, and Ideal write it L F or L:A. The first Logic Combi, System and Heat (2011) and the Independent show a letter and a digit together in one small LCD: F1, L2, LC. The 2012–2015 Logic ES, Logic Code Combi, i-mini, Independent C and ProCombi have two little windows labelled status and burner, the letter in one and the character in the other, and that is the generation whose numbering differs — L5 is five resets, not a thermistor, and it adds C0, C2, F0 and L3. The Logic ESP1 (2015–2023) pads to two characters, F 01 and L 02, with the code alternating with the flow temperature. The Logic Combi2, System2 and Heat2 (2023 on) and i-mini2 use three characters, L 0C, F 0U, L 0d, and add F 10 to F 16 for the pump, gas valve and spark generator. Logic+, Logic Max and every Vogue have a text screen and print the fault in words — Ignition Lockout, Pump Rotor Blocked, Thermal Fuse Lockout — with the checks listed beneath. Search any of those phrases here and you land on the matching code page.
How to reset a Ideal
It depends on the display. Logic, Logic ESP1, Logic Combi2 and i-mini: press the Restart button once — the button with the flame-and-cross symbol to the right of the dials. Logic+, Logic Max, Vogue Gen2 and Vogue Max: press the RESTART soft key under the screen when the fault screen offers it; faults that only offer Menu are not resettable from the front and want an installer. The first Vogue (2013–2017) has a physical button marked r on the control panel instead, and its screens say Reset boiler by pressing r. Isar, Icos, Mexico HE, Elise and Esprit: hold the reset button for two seconds; on the versions with a built-in programmer the Select button does the same job when held for more than three seconds. Two limits are Ideal's own and worth knowing before you press anything. The boiler tries to light by itself first — five attempts on Logic and Vogue, three on Isar, Icos and Mexico — so an ignition lockout has already been retried before you see it. And your presses are counted: five resets inside fifteen minutes gives LC on Logic, L5 on the two-window ES boards and Too Many Resets on a text screen, and that can only be cleared by switching the boiler off at the mains and on again. Stop pressing and call a Gas Safe registered engineer when the same lockout returns twice, when the code is a false flame, gas valve or spark generator fault, when you can smell gas, or when a carbon monoxide alarm has sounded. A gas smell is for the National Gas Emergency number on 0800 111 999 before anyone touches the boiler.
Most common Ideal faults
The Ideal codes people look up most.
- F1Get it checkedSystem pressure has dropped below the minimum the boiler will run at. Topping it back up to 1.2 bar usually clears it straight away.
- 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.
- F2Get it checkedThe flame was lost during operation. Ideal direct you to check the gas supply first, and that is genuinely the right order.
- L1Get it checkedThe boiler is not seeing enough water flow through it to run safely, so it has stopped. Usually a pump, an air lock, or a blocked filter.
Every Ideal fault code
50 published codes. Filtering happens in the page — every one is in the HTML.
Showing 50 of 50 codes
Ideal models
Codes can differ between generations. Check yours.
- Esprit HE, Esprit 2 and Elise2006–2012
- Icos HE and Icos System2004–2011
- Independent and Independent C2011–2016
- Isar HE2004–2011
- Logic Code Combi ES and ESP12013+
- Logic Combi2011+
- Logic Combi2, System2 and Heat22023+
- Logic Max2019+
- Logic System and Logic Heat2011+
- Logic+ Combi, System and Heat2011+
- Mexico HE2005+
- Vogue2013–2017
- Vogue Gen22017+
- Vogue Max2016+
- i-mini and i-mini22012+
Guides that help with Ideal faults
Boiler fault codes explained: what they actually tell you
Codes look like diagnoses and are not. Understanding which family a code belongs to turns a meaningless number into a genuinely useful starting point.Read the guideHow to repressurise a boiler
The five-minute job that resolves more no-heating calls than any other. Here is how to do it properly, and how to tell when topping up is the wrong answer.Read the guideWhat a Gas Safe engineer actually checks in a boiler service
Most people pay for this once a year and stand in another room while it happens. Here is what should be going on, which test cannot be faked, and how to tell a real service from twenty minutes and an invoice.Read the guideWhat to do when your condensate pipe freezes
The single most common winter boiler fault, and one of the few you can genuinely fix yourself in fifteen minutes with a kettle and some patience.Read the guide
Looking for Ideal’s own support? idealheating.com. We are not affiliated with Ideal.