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: Insufficient water pressure in the system
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 reasons are a slow leak hidden somewhere in your pipework or radiators, or because you recently bled your radiators without topping the system back up.
This issue often appears when you turn your heating back on for the first time in autumn, as cooling pipes can contract and reveal small leaks or pressure drops.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Open the small valves on the filling loop slowly until you hear water entering the system.Watch the pressure gauge and close the valves tightly once the needle 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 04 — no call-out fees, no surprises.
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Vokera Linea 24/28 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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