BoilerFaultCodesPotterton Pressure Gauge below 0.5 Fault Code
Also written as PRESSUREGAUGEBELOW05 — same fault.
The Potterton Pressure Gauge below 0.5 fault code means: your boiler has stopped working because the water pressure is too low, often caused by a small leak or air in the radiators.. It appears on 1 Potterton model in our database.
Technical description: If the pressure falls below 0.5, this may indicate a leak on the central heating system.
What causes the Potterton Pressure Gauge below 0.5 fault?
This fault occurs when the sealed water circuit inside your heating system loses enough water to drop below the safe operating limit. The most common reasons are tiny leaks from radiator valves or the automatic air vent, as well as air being released from the system through the radiators. Without enough water pressure, the boiler cannot safely circulate heat and shuts down to prevent internal damage.
This issue is frequently seen in autumn when the heating is turned back on for the first time, as the change in temperature can cause joints to weep or trapped air to move through the pipes.
DIY fix possible
Locate the silver braided filling loop underneath or near the boilerSlowly open the one or two taps on the filling loop until you hear water enteringWatch the pressure gauge and close the taps when it reaches 1.5 bar
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Gas Safe Register →Potterton models that show the Pressure Gauge below 0.5 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton Pressure Gauge below 0.5 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