BoilerFaultCodes.com

Potterton Promax Ultra, Gold/Titanium Fault Codes

CombiSystem Natural GasLPG 12-40 kW 2012-present
GC Numbers: 47-393-3547-393-3647-393-3747-393-3847-393-3947-393-4041-592-2541-592-2641-592-2741-592-2847-393-4147-393-4247-393-4347-393-4441-592-3141-592-3241-592-33

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Most common fault codes

E09
Your boiler has detected an electrical connection issue with the gas control system, preventing it from lighting safely.
Gas Safe engineer required · £120-£350
E15
Your boiler has lost its connection to the gas valve, meaning it cannot safely ignite to provide heating or hot water.
Gas Safe engineer required · £140-320
E20
Your boiler has lost its ability to measure the temperature of the water used for your radiators, causing the system to stop working for safety.
Gas Safe engineer required · £100-£180

All 28 fault codes

Code Severity Plain English
E09 High Your boiler has detected an electrical connection issue with the gas control system, preventing it from lighting safely.
E10 Low Your boiler has lost communication with the sensor that monitors the temperature outside your home, which may affect how efficiently it heats your radiators.
E15 High Your boiler has lost its connection to the gas valve, meaning it cannot safely ignite to provide heating or hot water.
E20 High Your boiler has lost its ability to measure the temperature of the water used for your radiators, causing the system to stop working for safety.
E28 High Your boiler has detected a problem with the sensor that monitors the temperature of the exhaust gases, causing it to shut down for safety.
E40 High Your boiler has detected a problem with the sensor that monitors the temperature of the water coming back from your radiators, preventing it from heating correctly.
E50 High Your boiler is having trouble measuring the temperature of your hot water, which usually means it won't provide hot water to your taps.
E53 High Your boiler is struggling to breathe because something is blocking the passage of air or exhaust gases through the flue pipe.
E55 High Your boiler's internal computer has detected that its gas and air settings need recalibrating to ensure it burns fuel efficiently and safely.
E78 High Your boiler's internal sensor is struggling to accurately read the water pressure, which prevents the system from operating safely.
E92 High Your boiler has detected an issue while trying to automatically adjust its internal settings for a clean and efficient flame.
E109 High Your boiler is struggling to move water around the system properly, which is causing it to overheat and shut down for safety.
E110 High Your boiler has become too hot and has shut itself down for safety, likely because the water isn't moving through the system correctly.
E117 Emergency Your boiler has shut down because there is too much water pressure in the system, which could lead to leaks if not addressed.
E118 High Your boiler has stopped working because the water pressure in the central heating system has dropped too low.
E125 High Your boiler has detected that hot water is not moving around the system properly, causing it to shut down to prevent overheating.
E128 High Your boiler was working but the flame has unexpectedly gone out, causing the system to stop for safety reasons.
E129 High Your boiler has failed to keep its flame lit while trying to automatically adjust its settings for efficient burning.
E130 High Your boiler has switched itself off because it has detected that the exhaust gases are becoming too hot, which is a safety feature to prevent damage.
E133 High Your boiler has failed to light, which means it cannot provide the gas flame needed to heat your water and radiators.
E135 High Your boiler's internal computer has encountered a software glitch or a communication failure that is preventing it from starting up safely.
E154 High Your boiler has detected that water is not circulating correctly through the main heat exchanger, often caused by a blockage or a pump issue.
E160 High Your boiler has stopped working because the fan that clears out exhaust gases isn't spinning at the correct speed.
E270 High Your boiler has detected that there is no water moving through the system while it is trying to heat up, causing it to shut down to prevent overheating.
E317 High Your boiler has detected an issue with the electrical frequency of your home's power supply, meaning the electricity isn't entering the unit at the correct rate for it to operate.
E321 Medium Your boiler's temperature sensor for hot water has stopped communicating correctly, which means you may have inconsistent or no hot water at your taps.
E384 Emergency Your boiler thinks a flame is burning even though the gas should be turned off, which causes it to shut down for safety.
E385 High Your boiler has stopped working because it isn't receiving enough electrical power from the mains supply or has suffered a sudden power drop.

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