BoilerFaultCodesFerroli F37 Fault Code
The Ferroli F37 fault code means: your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.. It appears on 16 Ferroli models in our database.
Technical description: Incorrect system water pressure error – possible sensor damaged or pressure too low
What causes the Ferroli F37 fault?
This fault occurs when the internal water pressure drops below the minimum level required for the boiler to fire up safely. The most common reason is a slow leak somewhere in your radiator network or a faulty expansion vessel that can no longer manage the system's pressure. It can also happen if you have recently bled your radiators and haven't topped the water level back up.
This fault is more common in autumn when homeowners turn their heating back on for the first time after summer, revealing pressure losses that occurred while the system was idle.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Slowly open the one or two small valves on the filling loop to allow water into the system.Watch the pressure gauge and close the valves tightly once the needle reaches between 1.0 and 1.5 bar.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Ferroli models that show the F37 fault code
Click a model for the full fault code list and model-specific repair notes.
- Arean Repair: £80-150
- Arena 30A Repair: £80-120
- BlueHelix Pro 25C Repair: £60-120
- BlueHelix Pro 32C Repair: £60-120
- Bluehelix Tech Repair: £60-120
- Domi Compact Repair: £80-120
- Domiproject Repair: £60-160
- Econcept 100 Repair: £80-150
- F 30 B Repair: £80-£150
- iBoiler 24 Repair: £80-160
- iBoiler 28 Repair: £0-150
- Maxima 35 S Repair: £80-150
- Modena HE Repair: £0-160
- Optima 201 Repair: £80-150
- Optimax Repair: £0-160
- Xignal Repair: £80-120
Source
Ferroli F37 fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026