Ideal F3 Fault Code (Logic Code Combi ESP1)

Safety disclaimer

Fault code summary

Manufacturer

Ideal

Fault code

F3

Fault type

Fan, Flue

Severity

high

Reset

Ideal recommends restarting the boiler once; do not repeatedly restart an unresolved fault.

Applicable models

Logic Code Combi ESP1 26, Logic Code Combi ESP1 33, Logic Code Combi ESP1 38

Quick answer

Fan fault.

What does this fault code mean?

Fan fault.

Common causes

• The boiler fan has a fault.

Symptoms

• The boiler displays F3.

What can the homeowner safely check?

• Ideal recommends restarting once; contact Ideal or a Gas Safe registered engineer if it still fails.

Boiler reset information

Ideal recommends restarting the boiler once; do not repeatedly restart 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 fan operation and the flue/air path.

Applicable boiler models

• Logic Code Combi ESP1 26
• Logic Code Combi ESP1 33
• Logic Code Combi ESP1 38

Related fault codes

• F1 — Logic Code Combi ESP1

  Low water pressure.

  Read fault code
• F7 — Logic Code Combi ESP1

  Low mains voltage.

  Read fault code

Manufacturer documentation

F3 - Fan Fault — Restart your boiler if you see this code ... if it still fails to operate ... contact a Gas Safe registered engineer.

Last verified

2026-09-12

Frequently asked questions