Ferroli · Bluehelix Tech RRT

F37System water pressure incorrect or too low

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 the pressure gauge with the system cold.
If it is below the range stated in the boiler manual, repressurise only by following that model's user instructions.
Stop and book an engineer if pressure drops again, rises excessively, or there is a visible leak.

How an engineer may fix it

Check for leaks, trapped air, the pressure sensor, pump and expansion vessel; repair the underlying fault before recommissioning.

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.