F09
FAULT CODE
Ferroli
Overtemperature Protection — Return Sensor
High Severity
Engineer Required
On Ferroli Bluehelix Tech boilers, F09 indicates the overtemperature protection has activated based on the return sensor — no water circulation or air in the system.
Step-by-Step Fix Guide
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Step 1
Turn off and allow to cool
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Step 2
Check system pressure and bleed radiators
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Step 3
Reset once
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Step 4 Engineer only
If fault returns, call a Gas Safe engineer
Gas Safe Reminder
Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.