What does the Ideal Mini F40 fault code mean?
The F40 fault code on the Ideal Mini boiler indicates a fault with the domestic hot water (DHW) flow switch. This typically means that the flow switch is either stuck, faulty, or not detecting water flow correctly.
Common Causes
- Faulty Flow Switch: The flow switch may have failed due to wear and tear or internal damage, preventing it from functioning properly.
- Blocked Water Path: A blockage in the water supply line can restrict flow, causing the flow switch to not activate as it should.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and repair this issue, as it involves gas and electrical components that can be dangerous if handled improperly.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for the F40 fault code is around £150 to £250, primarily for the replacement of the flow switch and associated labour costs. This estimate reflects the specific parts and expertise required for the repair.