High
F47 on Ferroli Optimax HE 31 C

Your boiler is failing to detect the water pressure in the system, which prevents it from safely igniting to provide heating or hot water.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

N/A for UK market (Wiring interrupted / Sensor damaged)

From this model's manual
Verified against the Ferroli/Ferroli Optimax He 31 C 4726742 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F37View →

All 32 fault codes on the Optimax HE 31 C

Seeing a different code? Every code this model can display, in one place.

A01A02A03A04A05A06A41F04F05F07F10F11F12F13F14F15F20F21F24F34F35F37F39F40F41F42F43F50F51Low system pressureNo burner ignition

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