P.05 Low

Heatline P.05 Fault Code

Also written as P05 — same fault.

The Heatline P.05 fault code means: your boiler is currently refilling its internal water system, which is a normal process that should resolve itself automatically.. It appears on 2 Heatline 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: Filling the appliance

DIY fix possible

Wait 5-10 minutes for the boiler to complete the automatic filling cycle.Ensure your heating system pressure gauge is reading between 1.0 and 1.5 bar.If the code persists after 30 minutes, switch the boiler off and back on at the fused spur to reset it.

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Heatline models that show the P.05 fault code

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

Source

Heatline P.05 fault code information on this page is sourced and cross-checked against the official Heatline service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026