Ideal Heating · Logic Code Combi ESP1
F1Low water pressure
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
- Check the pressure gauge with the system cold.
- If it is below the range stated in the boiler manual, repressurise only by following that model's user instructions.
- Stop and book an engineer if pressure drops again, rises excessively, or there is a visible leak.
How an engineer may fix it
Check for leaks, trapped air, the pressure sensor, pump and expansion vessel; repair the underlying fault before recommissioning.
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.