BoilerFaultCodesYour boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Incorrect system water pressure error – possible sensor damaged or pressure too low
What causes this 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
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A boiler cover plan would cover faults like F37 — no call-out fees, no surprises.
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Ferroli Modena HE is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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