What does the Ideal Mexico HE F99 fault code mean?
The F99 fault code on the Ideal Mexico HE indicates an unknown fault related to the domestic hot water (DHW) system. This can arise from various issues affecting the boiler’s ability to provide hot water.
Common Causes
- Faulty DHW Sensor: A malfunctioning sensor may not accurately detect the temperature or flow of water, leading to the F99 error.
- Blocked Heat Exchanger: A blockage in the heat exchanger can prevent proper heat transfer, disrupting the hot water supply.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it may involve gas or electrical components that require professional handling for safety reasons.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F99 fault could be around £150 to £250, primarily depending on whether the DHW sensor needs replacement or if the heat exchanger requires cleaning or servicing.