p 1.5 Low

Potterton p 1.5 Fault Code

Also written as P15 — same fault.

The Potterton p 1.5 fault code means: your boiler is simply displaying the current water pressure level, which is perfectly normal and shows that your system is functioning correctly.. It appears on 1 Potterton model in our database.

Monitor it

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: System pressure check (example value 1.5 bar). Control display warns if system pressure falls below 0.5 bar.

DIY fix possible

No action is required as this is a status update, not a fault.If the reading drops below 0.5 bar, you may need to top up the system pressure using the filling loop.Check your user manual for the location of your external filling loop if the pressure falls in the future.

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Potterton models that show the p 1.5 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Potterton p 1.5 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026