Boiler shows F70 after PCB replacement or configuration change

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Incorrect PCB part fitted, PCB not coded to boiler type, Faulty EEPROM configuration

Safety: Isolate power before accessing the PCB.

Steps:

Verify that the installed PCB matches the exact Protherm model and gas type.
Use Protherm service tools or service menu to configure the PCB for the boiler model (technician only).
If configuration fails or is not possible, replace the PCB with the correct part.

Hard 4/5

Main Control PCB

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