BoilerFaultCodesIdeal P0 Fault Code
The Ideal P0 fault code means: your boiler has detected that the water pressure is too low for it to operate safely, which usually means the system needs more water.. It appears on 1 Ideal model in our database.
Technical description: Low Pressure Error
What causes the Ideal P0 fault?
This fault occurs when the internal sensor detects that the system's water pressure has dropped below the minimum level required to circulate heat safely. The most common reasons are a slow leak in the radiator valves or pipework, or simply needing to top up the water levels after bleeding your radiators.
This fault is more common in autumn when homeowners turn their heating back on for the first time, as small leaks may have developed or the system pressure may have settled during the summer months.
DIY fix possible
Locate the metal braided filling loop underneath or near the boilerOpen the valves slowly until you hear water flowing and the pressure gauge reaches 1.5 barClose both valves tightly and reset the boiler
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Gas Safe Register →Ideal models that show the P0 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal P0 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