BoilerFaultCodesYour boiler has detected that the water pressure is too low, preventing it from heating your home safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: GO TO FRAME 74
What causes this fault?
This fault occurs when the system lacks enough water to operate safely, often caused by a small leak in the pipework or radiators. It can also happen after you have recently bled your radiators, which releases air but also lowers the overall system pressure. In some cases, a failing internal component like the expansion vessel may be preventing the boiler from maintaining the correct pressure levels.
This issue often appears in autumn when homeowners turn their heating back on for the first time, as joints may have contracted or minor leaks developed during the summer months.
DIY fix possible
Locate the filling loop (a flexible silver hose) underneath your boiler.Slowly open the valve(s) until you hear water flowing and watch the pressure gauge rise.Close the valves tightly once the needle reaches between 1 and 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 H1 — no call-out fees, no surprises.
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Ideal Elise H 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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