BoilerFaultCodes.com

Viessmann Vitodens 333 Fault Codes

Combi Natural GasLPG 26-35 kW 2004-2011 Discontinued
GC Number: 47-819-15

Replaced by: Vitodens 222-F

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Most common fault codes

9B
Your boiler has lost connection with its internal hot water storage sensor and cannot currently heat your water effectively or safely.
Gas Safe engineer required · £140-£260
9C
Your boiler has lost connection with the sensor that monitors the temperature of your hot water cylinder, meaning it cannot heat your water correctly.
Gas Safe engineer required · £120-£200
20
Your boiler's internal computer has detected a faulty or damaged temperature sensor, preventing the system from accurately measuring how hot the water is.
Gas Safe engineer required · £120-190

All 58 fault codes

Code Severity Plain English
0F Low Your boiler is reminding you that its scheduled annual service is now due, but it should continue to provide heating and hot water as normal.
9A Low Your boiler has lost communication with the sensor that monitors your solar heating panels, likely due to a damaged or disconnected wire.
9B High Your boiler has lost connection with its internal hot water storage sensor and cannot currently heat your water effectively or safely.
9C High Your boiler has lost connection with the sensor that monitors the temperature of your hot water cylinder, meaning it cannot heat your water correctly.
9F Medium Your boiler is struggling to communicate with the solar panel system used to help heat your water.
10 Low Your boiler's outside thermometer has developed a fault, causing the system to 'think' it is 0°C outside and adjust your heating accordingly.
18 Low Your boiler is confused about the weather outside because the external sensor has lost its connection, meaning the heating might not adjust correctly to the outdoor temperature.
20 High Your boiler's internal computer has detected a faulty or damaged temperature sensor, preventing the system from accurately measuring how hot the water is.
28 High Your boiler has lost communication with a sensor that monitors the temperature of the water flowing into your heating system, usually because of a loose or damaged wire.
30 High Your boiler has stopped working because its internal temperature sensor has developed an electrical fault and can no longer safely monitor the heat level.
38 High Your boiler has stopped working because it cannot accurately measure its own internal temperature due to a broken or disconnected sensor wire.
40 Medium Your boiler has detected a faulty temperature sensor in one of your heating zones, which is preventing that specific circuit from getting warm.
48 Medium Your boiler has lost communication with the temperature sensor that controls your second heating circuit, causing that specific zone to stop heating correctly.
50 High Your boiler is unable to heat your hot water because one of the internal temperature sensors has developed an electrical fault.
51 High Your boiler is unable to provide hot water because of a faulty internal sensor that has stopped communicating correctly.
58 High Your boiler is unable to heat your hot water because a sensor responsible for monitoring the cylinder temperature has lost its connection or stopped working.
59 High Your boiler is unable to heat your hot water because a sensor that monitors the temperature of the water cylinder has stopped communicating with the system.
92 Low Your boiler’s solar heating panel sensor has a wiring fault, meaning the system cannot correctly read the temperature of the water heated by the sun.
93 Low Your boiler’s solar heating connection has a faulty sensor that is incorrectly detecting a short circuit, preventing your solar panels from helping to heat your water.
94 Medium Your boiler has detected a problem with the sensor that measures the water temperature in your solar cylinder, which may affect how your hot water is heated.
A7 Medium Your boiler's control panel and the main internal computer are having trouble talking to each other, meaning the display might not work correctly or respond to your settings.
b0 High Your boiler has stopped working because it has detected a technical fault with the sensor that monitors the heat of the exhaust gases.
b1 High Your boiler's main control panel is having trouble talking to the internal computer, meaning you cannot adjust settings or operate the unit effectively.
b4 High Your boiler's internal computer is having trouble processing electrical signals correctly, which is preventing it from running its safety and efficiency tests.
b5 High Your boiler's main internal computer has encountered a communication error and cannot control the heating process correctly.
b7 High Your boiler has stopped working because it cannot communicate with its internal memory chip or the main control board is malfunctioning.
b8 High Your boiler has shut down because it cannot accurately measure the temperature of the exhaust gases, causing the burner to stop for safety.
bA Medium Your boiler is having trouble communicating with the control kit that manages the heating for your secondary radiator or underfloor heating zone.
bC Medium Your boiler has lost its connection with the remote control unit used to manage the heating and is currently operating in a basic backup mode.
bd Medium Your boiler has lost communication with your remote room thermostat or heating controller for the second heating circuit.
bE Medium Your wall-mounted remote control unit is not communicating correctly with the boiler because of a settings error.
bF Medium Your boiler's internal communication system has detected an issue with a plug-in connection module, meaning the main control board cannot talk to other system components properly.
C2 Low Your boiler is having trouble talking to the solar heating system, which may prevent your home from using energy from your solar panels efficiently.
C5 High Your boiler is having trouble communicating with its internal pump, which means water cannot circulate properly to heat your home.
C6 Medium Your boiler is having trouble communicating with the internal pump that manages one of your heating circuits, meaning that part of your heating may not be working correctly.
C7 Medium Your boiler is having trouble communicating with the internal pump that moves water around your radiators, which may lead to your heating not working effectively.
Cd Low Your boiler has lost its connection with the external remote control or internet communication module.
CE Medium Your boiler is having trouble 'talking' to an add-on device, such as an extra heating controller or an external sensor module.
CF High Your boiler's internal communication system has failed, meaning the different electronic parts are no longer talking to each other correctly.
dA Low Your boiler has lost its connection to the indoor thermostat sensor, meaning it can no longer adjust the heating based on the actual temperature inside your home.
db Low Your boiler has lost its connection to one of the temperature sensors used to control your heating, though it will likely keep running in a basic backup mode.
dd Low Your boiler has lost connection with its indoor temperature sensor, meaning it can no longer tell how warm your rooms are and has switched to a basic backup heating mode.
dE Medium Your boiler has lost connection to one of its internal temperature sensors, which means it cannot accurately monitor the heat for one of your heating zones.
E4 High Your boiler has stopped working because it is not receiving the correct electrical supply, preventing the burner from igniting.
E5 High Your boiler has stopped working because it cannot properly detect the flame it needs to stay lit safely.
E6 High Your boiler has shut down because it cannot safely vent exhaust gases or draw in fresh air, usually due to a blockage in the flue pipe or a hardware failure.
F0 High Your boiler has stopped working because its internal computer and burner system have detected a technical communication failure.
F1 High Your boiler has shut down because it detected that the exhaust gases have become too hot, which is a safety feature to prevent damage or dangerous operation.
F2 High Your boiler has shut down because it has overheated or detected a lack of water flow through the system.
F3 High Your boiler has shut down because it thinks it can see a flame before it has even started the ignition process.
F4 High Your boiler is failing to light the flame needed to heat your water and radiators, which has caused the system to shut down for safety.
F7 High Your boiler has shut down because it is unable to accurately measure the air pressure required for its burner to operate safely.
F8 Emergency Your boiler has detected a potential issue with the valve that controls the gas supply, meaning it isn't shutting off correctly for safety.
F9 High Your boiler's fan is not spinning fast enough to safely start the burner, causing the system to shut down for safety.
FA High Your boiler has stopped working because the internal fan is spinning too fast during the startup process, preventing the burner from igniting safely.
Fd High Your boiler's internal computer has detected a problem with the burner's ignition system and has shut down as a safety precaution.
FE High Your boiler has shut down because electronic interference or a faulty internal circuit board is preventing the burner from starting safely.
FF High Your boiler's internal computer has encountered a critical communication error and has shut down the burner for safety.

Viessmann Vitodens 333 is discontinued — time for a new one?

Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.

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