BoilerFaultCodesPotterton E193 Fault Code
The Potterton E193 fault code means: your boiler has sensed that water is not circulating properly before it starts the heating process, which is usually caused by an air lock or a blockage.. It appears on 8 Potterton models in our database.
Technical description: Pre-Circulation Fault
What causes the Potterton E193 fault?
This fault occurs when the boiler's internal sensors detect that water isn't moving through the unit quickly enough during its initial checks. This is usually caused by a large pocket of air trapped inside the pipework or a failing pump that no longer has the power to push water around the system. In some cases, a build-up of sludge or debris can also create a physical blockage that restricts the flow.
This issue is more frequent in autumn when the heating is turned back on after a long summer break, as pumps can seize and air can settle in the pipes during periods of inactivity.
DIY fix possible
Check that your system pressure is between 1 and 1.5 bar on the pressure gaugeEnsure all radiator valves and isolation valves under the boiler are fully openGently bleed your radiators to remove any trapped air
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Gas Safe Register →Potterton models that show the E193 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton E193 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