Verified boiler fault code
Ideal F1 Fault Code (Logic Code Combi ESP1)
Low water pressure.
Safety disclaimer
Fault code summary
- Manufacturer
- Ideal
- Fault code
- F1
- Fault type
- Low pressure
- Severity
- Not specified
- Reset
- Not specified
- Applicable models
- Logic Code Combi ESP1 26, Logic Code Combi ESP1 33, Logic Code Combi ESP1 38
Quick answer
Low water pressure.
What does this fault code mean?
Low water pressure.
Common causes
- System water pressure is below the 1 to 1.5 bar range stated by Ideal.
Symptoms
This information was not provided in the verified manufacturer source.
What can the homeowner safely check?
- Check the system pressure gauge; Ideal says it should be between 1 and 1.5 bar.
Boiler reset information
Reset information was not provided in the verified manufacturer source. Do not repeatedly reset an unresolved fault.
When should I call an engineer?
Contact a suitably qualified heating engineer when the fault persists, the boiler locks out, or the manufacturer instructions do not resolve it. For gas appliance work in the UK, use a Gas Safe registered engineer.
Engineer diagnosis
- Assess system pressure and any continuing pressure loss.
Applicable boiler models
Related fault codes
Manufacturer documentation
Ideal Logic Code Combi ESP1 troubleshooting manualF1 - Low Water Pressure — check that the system water pressure is between 1 and 1.5bar on the boiler’s system pressure gauge.
Last verified
2026-09-12
Frequently asked questions
What does Ideal F1 mean?
Low water pressure.