Vaillant Turbomax 824/828 Fault codes & diagnostics

Your boiler is unable to read the temperature of the water flowing out of it because a sensor or its connection has failed, causing the system to stop working as a precaution.

Your boiler has lost the signal from the sensor that monitors the temperature of water returning to it, meaning it cannot safely regulate its heat.

Your boiler has detected a faulty electrical signal from its internal temperature sensor, causing it to shut down to prevent potential overheating.

Your boiler has detected an electrical fault in a temperature sensor that monitors the water returning to the system, causing it to shut down for safety.

Your boiler has automatically shut itself down because it reached a dangerously high temperature and needs to cool off before it can restart safely.

Your boiler has detected that there is either too little water inside the system or that the internal pump is failing to move the water around as it should.

Your boiler has detected that water is not circulating properly through the system, causing the heater to shut down to prevent damage.

Your boiler has detected that the water is heating up far too quickly, likely because there is air trapped inside or the pump is struggling to circulate water properly.

Your boiler has detected an internal fault that is preventing it from safely starting the flame, meaning you currently have no heating or hot water.

Your boiler is failing to ignite because it cannot detect or process a flame, meaning you currently have no heating or hot water.

Your boiler is trying to start but cannot maintain a flame, likely due to a gas supply issue or a loss of pressure in your heating system.

Your boiler has detected that the fan, which manages air intake and exhaust, is not running at the correct speed, so it has stopped working to keep your home safe.

Your boiler has detected an issue with its internal airflow system, causing it to shut down for safety to prevent improper combustion.

Your boiler has detected an issue with the internal ventilation system that prevents it from starting safely, so it has shut down to protect itself.

Your boiler has lost its memory regarding what type of gas it should be using, which prevents it from operating safely.

Your boiler has detected a problem with the internal wiring that sends signals between its control components, meaning it cannot operate safely and has shut itself down.

Your boiler's internal wiring has detected a communication failure, meaning the control board cannot properly talk to the other parts of the heating system.

Your boiler has detected an internal communication error with its main control system, causing it to shut down for safety.

Your boiler has detected an internal failure in its main control system, meaning it cannot operate safely and has shut down to protect itself.

Your boiler has detected that a flame is still being sensed even after it should have switched off, which is a safety issue that prevents it from restarting.

Your boiler's computer is having trouble communicating internally, which has caused it to shut down for safety reasons.

Your boiler's computer is struggling to read its internal temperature sensors, so it has safely shut down to prevent overheating.

Your boiler has detected that its internal computer is overheating, which has caused it to shut down for protection.

Your boiler's control panel has lost communication with the main internal computer, meaning it cannot operate or receive instructions.

Your boiler's main control computer is failing to communicate correctly, meaning the system has safely shut itself down to prevent unpredictable operation.