FnIdeal
Ideal Fn: flame loss
Checked against Ideal's own documentation: Ideal Logic Combi ESP1 installation and servicing instructions (UIN 222353) and 1 more source. Last reviewed October 2026. How we check
Check these first, then call an engineer
Ideal describes Fn on Logic Combi (ESP1) boilers as: flame loss. Ideal's general fault code guide gives the same first checks for flame loss, which it lists under F2 and L2.
What you can safely do
- Reset the boiler.
- If you have a pay-as-you-go gas meter, check it has credit.
- Check your other gas appliances, such as the hob, are working.
- Check the yellow gas isolation valve is open.
Call a Gas Safe engineer if
- The code comes back. Ideal says to call Ideal and quote the code.
- You hear gurgling from the boiler: Ideal says to contact your installer.
- You smell gas at any point. Leave the property and call 0800 111 999.
Find a Gas Safe engineer near you
Opens the official Gas Safe Register search.
Applies to Logic Combi (ESP1). Codes can differ between models, so check your manual.