Ferroli · Bluehelix Tech RRT

F34Supply voltage below 170 V

This code applies to Bluehelix Tech RRT 24C, Bluehelix Tech RRT 28C, Bluehelix Tech RRT 34C, Bluehelix Tech RRT 18S, Bluehelix Tech RRT 24S, Bluehelix Tech RRT 30S. Fault codes narrow down the likely problem, but they do not replace a model-specific diagnosis.

What you can safely check

Check for a wider power cut or a tripped consumer-unit circuit without removing the boiler case.
Use a qualified electrician or Gas Safe engineer for further diagnosis.

How an engineer may fix it

Verify supply voltage, polarity, earthing, fuses, harnesses and appliance electronics; correct the electrical supply or replace the failed component.

Code availability varies slightly between combi and system outputs; confirm the exact model manual.

Manufacturer source: Ferroli — Bluehelix Tech RRT 24C Instructions for Use, Installation and Maintenance. Checked 15 August 2026. The appliance manual and an engineer’s on-site diagnosis take precedence. Never remove the boiler case yourself.