Ideal Heating · Logic Code Combi ESP1
F9 / L9 / F8 / L8PCB unconfigured or faulty
This code applies to Logic Code Combi ESP1 26, Logic Code Combi ESP1 33, Logic Code Combi ESP1 38. Fault codes narrow down the likely problem, but they do not replace a model-specific diagnosis.
What you can safely check
- Power-cycle or reset once only if the user manual specifically permits it.
- If the message remains, arrange an engineer.
How an engineer may fix it
Check configuration, coding, communication buses, plugs, wiring, power supply and control boards; configure, repair or replace the failed control component.
Manufacturer source: Ideal Heating — Logic Code Combi ESP1 Installation & Servicing (UIN 222364 A04). Checked 15 August 2026. The appliance manual and an engineer’s on-site diagnosis take precedence. Never remove the boiler case yourself.