BoilerFaultCodesYour boiler is displaying its current water pressure, which usually indicates the pressure has dropped too low for the system to heat your home.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Heating system pressure (in bar)
What causes this fault?
This code appears when the water pressure inside your heating system has dropped below the minimum level required for the boiler to operate safely. It is usually caused by a small leak somewhere in the pipework or radiators, or because the system was recently bled without being topped back up. When the pressure is too low, the boiler will stop firing to prevent internal damage from overheating.
This fault is frequent in autumn when homeowners turn their heating back on for the first time, as dormant leaks or air pockets often cause the pressure to drop.
DIY fix possible
Locate the filling loop (a flexible silver hose) underneath or near the boiler.Slowly open the valve or valves until you hear water moving.Watch the display until the pressure reaches between 1.0 and 1.5 bar, then close the valves tightly.
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A boiler cover plan would cover faults like P — no call-out fees, no surprises.
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