BoilerFaultCodesYour boiler has noticed that the water pressure is getting a bit low and needs a small top-up to keep running efficiently.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: The system pressure is falling and it is advised to top up.
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below the ideal operating level. The most common reasons are small leaks from radiator valves, air being released through the vents, or the expansion vessel losing its air charge over time.
This issue is frequently seen in autumn when the heating is turned on for the first time after summer, as the change in temperature can highlight minor leaks or trapped air.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Slowly open the valve(s) until you hear water entering the system.Watch the pressure gauge and close the valves tightly once it reaches 1.5 bar.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like P 0.9 — no call-out fees, no surprises.
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Potterton Powermax 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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