BoilerFaultCodesIdeal L 01 Fault Code
Also written as L01 — same fault.
The Ideal L 01 fault code means: your boiler has got too hot and has shut itself down for safety, meaning you have no heating or hot water until the system cools and is reset.. It appears on 4 Ideal models in our database.
Technical description: Overheat Lockout
DIY fix possible
Check that all radiator valves are fully open to allow water to circulate.Ensure there is enough water in the system by checking the pressure gauge is between 1 and 1.5 bar; top up if necessary.Once the boiler has cooled, press and hold the 'Mode/Reset' button for 3 seconds to clear the lockout.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like L 01: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Ideal models that show the L 01 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal L 01 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
- Ideal i-mini2 C24 manual (PDF)
- Ideal Independent System2 S15 manual (PDF)
- Ideal Logic Max Combi 2 manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026