What does the Ideal Mini F79 fault code mean?
The F79 fault code on the Ideal Mini indicates a problem with the domestic hot water (DHW) system pressure differential. This typically means that there is an issue with the pressure difference between the inlet and outlet of the DHW system, which can affect the boiler’s ability to provide hot water.
Common Causes
- Blocked DHW Heat Exchanger: A blockage in the heat exchanger can prevent proper water flow, leading to pressure differential issues.
- Faulty Pressure Sensor: A malfunctioning pressure sensor may incorrectly read the pressure levels, triggering the F79 fault code.
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 addressing the F79 fault could be around £150 to £250, depending on whether a pressure sensor needs replacing or if the heat exchanger requires cleaning or replacement.