PH Low

Ideal PH Fault Code

The Ideal PH fault code means: your boiler is not broken; it is simply in 'installer mode' which is used during setup or testing and can be exited by adjusting the control knobs.. It appears on 3 Ideal 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: Installer Mode setting code

What causes the Ideal PH fault?

This occurs because the control knobs on the front of the boiler have been placed into a specific sequence used by engineers to test the system's performance. It is usually triggered accidentally during cleaning or when someone is trying to adjust the temperature settings manually. Because the boiler is waiting for programmed instructions from an installer, it pauses normal heating operation until the mode is deactivated.

DIY fix possible

Turn the DHW (Hot Water) thermostat knob fully clockwise then fully anticlockwise.Turn the CH (Heating) thermostat knob fully clockwise then fully anticlockwise.The display should return to the standard temperature reading.

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Ideal models that show the PH fault code

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

Source

Ideal PH 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