Saunier Duval Isofast Fault codes & diagnostics

Your boiler is struggling to clear exhaust fumes or draw in fresh air, so it has safely shut down to prevent any risk.

Your boiler is failing to light the fuel inside, meaning it cannot provide you with heating or hot water until the ignition process is fixed.

Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage to its internal components.

Your boiler is struggling to read its own temperature, so it has turned itself off as a precaution to prevent overheating.

Your boiler is struggling to accurately measure the temperature of the water stored inside it, so it has stopped heating to prevent potential overheating.

Your boiler has lost the ability to accurately measure the water pressure inside the system, which is preventing it from running safely.

Your boiler has detected that the internal exhaust fan is not spinning correctly, which stops the system from operating to ensure safe ventilation.

Your boiler is unable to circulate water effectively because the internal pump that moves heat around your home has become stuck.

Your boiler's electronic display and control panel are failing to communicate with the main system, meaning settings may not be applied or the boiler may stop responding.

Your boiler has detected an internal electronic error within its main control unit, preventing it from operating correctly.

Your boiler has detected that the water inside the unit has become dangerously hot, so it has safely shut itself down to prevent overheating.

Your boiler's electronic brains are struggling to talk to each other, so the system has stopped working to protect itself.

Your boiler has stopped working because the water pressure inside the heating system has dropped too low.

Your boiler is struggling to detect the water flow required to heat your home or provide hot water, often due to a blockage or a sensor not reading correctly.

Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage.

Your boiler is struggling to accurately detect how much water is inside the system, which is preventing it from safely starting your heating or hot water.

Your boiler's electronic control panel is experiencing a communication error, which means it cannot process your settings or display status updates correctly.

Your boiler's internal computer is experiencing a communication error, meaning it can no longer safely control the heating or hot water functions.

Your boiler is struggling because the electricity supply it is receiving is not strong enough to power it correctly.

Your boiler's digital display or control panel is having communication issues, which means the machine cannot receive your instructions on how to run.

Your boiler has lost its connection to the sensor that monitors the flow of water, meaning it cannot confirm that water is circulating properly through your heating system.

Your boiler’s digital control panel is struggling to talk to the main internal computer, which is preventing the system from operating correctly.

Your boiler has detected that the water returning from your radiators is dangerously hot, causing it to shut down to prevent damage.

Your boiler has detected that the water inside the system is heating up much faster than it should, which has caused it to shut down for safety.

Your boiler has detected that the water is heating up or cooling down much faster than it should, indicating a problem with the internal circulation of water.

Your boiler is failing to ignite because it is not receiving the gas supply it needs to produce a flame.