What does the Baxi Duo-tec F69 fault code mean?
The F69 fault code on a Baxi Duo-tec boiler indicates a problem with the domestic hot water (DHW) heat exchanger. This fault typically suggests that the heat exchanger is either blocked or has developed a leak, preventing efficient heating of water.
Common Causes
- Blocked Heat Exchanger: Debris or limescale buildup can obstruct the flow of water, leading to inadequate heating.
- Leaking Heat Exchanger: A physical failure in the heat exchanger can cause water to leak, which may trigger the fault code.
Can I fix it myself? (DIY)
It is highly recommended to call a Gas Safe Engineer to diagnose and repair the issue, as working on gas appliances can be dangerous and requires professional expertise.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the F69 fault on a Baxi Duo-tec boiler is around £300 to £450. This includes the cost of parts, such as a new heat exchanger, and labour charges for a qualified engineer.