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'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 failed to light the flame, which means it currently cannot produce any heating or hot water.

Your boiler is struggling to clear exhaust gases safely, so it has shut down to prevent any risk of fumes entering your home.

Your boiler is struggling to clear exhaust gases properly, so it has safely shut itself down to prevent any risk.

Your boiler has sensed that it is getting dangerously hot and has shut itself down to prevent any internal damage.

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

Your boiler has stopped being able to detect the flow of water necessary to heat your home's radiators, so it has shut 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 is struggling to read the temperature of the water returning to it, so it has safely shut down your heating and hot water to prevent any damage.

Your boiler's internal computer is reporting an error because it can no longer communicate correctly with its internal systems.

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 has detected an issue with the internal mechanism that controls the gas supply, meaning it cannot safely start up to provide heating or hot water.

Your boiler is having trouble moving an internal valve that controls how hot water is sent to your taps or radiators, meaning it cannot properly switch between heating your home and your hot water supply.

Your boiler is struggling to detect the flow of gas required to light the burner, meaning it cannot heat your water or radiators.

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 switched itself off because the water pressure inside the system has dropped too low to operate safely.

Your boiler has detected that the water pressure inside the system has risen too high, causing it to shut down for safety.

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