BoilerFaultCodesPotterton 193 Fault Code
The Potterton 193 fault code means: your boiler is struggling to move water around the system correctly, which is likely caused by trapped air or a failing pump.. It appears on 1 Potterton model in our database.
Technical description: Primary circulation fault (Ensure that primary circulation is OK & that there is no blockage)
What causes the Potterton 193 fault?
This fault occurs when the boiler detects that water isn't flowing through the internal heat exchanger at the required speed, causing a rapid rise in temperature. The most common reasons are air bubbles trapped within the pump or a mechanical failure of the pump motor which prevents it from pushing water around your radiators. It can also happen if the system pressure is too low or if an internal valve has become stuck.
This issue is more frequent in autumn when heating systems are turned back on after being idle all summer, which often causes pump components to seize or air pockets to shift.
DIY fix possible
Check that your radiator valves are fully openGently bleed your radiators to remove any trapped airEnsure the system pressure is between 1.0 and 1.5 bar on the gauge
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Gas Safe Register →Potterton models that show the 193 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Potterton 193 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