P1.0-2.9 bar Low

Potterton P1.0-2.9 bar Fault Code

Also written as P1029BAR — same fault.

The Potterton P1.0-2.9 bar fault code means: your boiler is displaying its current water pressure, which is within the normal operating range while the system is running.. It appears on 2 Potterton models 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: Normal pressure, system warm/hot

What causes the Potterton P1.0-2.9 bar fault?

This is not actually a fault, but the boiler displaying that the internal water pressure is at a healthy level. As the water in your radiators heats up, it expands, causing the pressure reading to naturally rise toward the upper end of this range. It indicates that the system is functioning correctly and has the right amount of water to circulate heat around your home.

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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Potterton models that show the P1.0-2.9 bar fault code

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

Source

Potterton P1.0-2.9 bar 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