BoilerFaultCodesPotterton E430 Fault Code
The Potterton E430 fault code means: your boiler has detected that the water pressure is too low to operate safely and has temporarily stopped working.. It appears on 1 Potterton model in our database.
Technical description: Water pressure test
What causes the Potterton E430 fault?
This fault occurs when the system's internal sensors detect that the water pressure has dropped below the minimum level required to heat your home safely. The most common reason is a minor leak in the pipework or radiators, or it could simply be that air was recently bled from your radiators, leaving the system under-filled.
This fault often appears in autumn when homeowners turn their heating back on for the first time after summer, revealing pressure drops that occurred while the system was dormant.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath your boiler.Open the small valves on the hose slowly until you hear water entering the system.Watch the pressure gauge and close the valves once the needle reaches between 1.0 and 1.5 bar.
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Gas Safe Register →Potterton models that show the E430 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton E430 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