Ideal HHHHH:::::AAAAA Fault Code
Also written as HHHHHAAAAA — same fault.
The Ideal HHHHH:::::AAAAA fault code means: your boiler has stopped heating your radiators and water because the internal water pressure has dropped too low.. It appears on 3 Ideal models in our database.
Technical description: Boiler is not working for central heating or hot water; check pressure gauge on boiler shows a minimum of 1 bar.
DIY fix possible
Locate the filling loop (usually a silver braided hose with one or two valves) underneath the boiler.Slowly open the valve(s) to let water enter the system while watching the pressure gauge on the front panel.Stop when the needle reaches the green zone, ideally around 1.5 bar, and ensure the valve is tightly closed.
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Gas Safe Register →Ideal models that show the HHHHH:::::AAAAA fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal HHHHH:::::AAAAA fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026