Vaillant Boiler Fault Codes
Vaillant Boiler Fault Codes
If you encounter a fault code problem with your Vaillant boiler, your focus is getting this problem resolved as quick as possible to avoid the situation continuing.
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What are the common Vaillant Boiler Fault Codes?
F.00 - NTC Faults
Faults with the NTC thermistor, which provides temperature readings to the boiler's control system.
F.10, F.11, F.12, F.13, F.14 - Ignition Problems
Failure to ignite. This could be due to a problem with the boiler's ignition, gas supply or a blocked condensate pipe.
F.20 - Safety Switch Off: Low-Water Content
The boiler has shut off due to low water pressure.
F.22 - Dry Fire, Low Water Pressure
The boiler pressure is too low and needs to be repressurised.
F.23 - Safety Switch Off: Temperature Limiter
The boiler has become too hot.
F.24, F.37 - Fault: Water Shortage
The boiler has detected a lack of water in the system.
F.27 - Mains Undervoltage
An issue with the voltage supply.
F.28, F.29 - Failure During Start-Up: Ignition Fault
The boiler has failed to ignite.
F.32 - Fan Speed Variance: Fan Running Too Slow
The boiler's fan is running too slow.
F.49 - eBUS Under Voltage
This indicates a fault with the power supply.
F.61, F.62, F.63, F.64, F.65 - Electronic Faults
These indicate various electronic faults within the boiler.
F.67 - Fluctuation in Mains Voltage
The mains electrical supply to the boiler is fluctuating.
F.70 - Unrecognisable Configuration
This suggests that there's an issue with the configuration of the boiler's settings.
F.71 - Flow NTC Open Circuit
There is a problem with the NTC sensor in the boiler.
F.72 - Flow/Water Pressure
The boiler is experiencing water pressure issues.
F.74 - Flow and Return Sensors
The flow and return sensors are reporting different readings.
F.75 - Pump or Water Shortage
The pump isn't working correctly or there's a lack of water in the system.
F.76 - Overheating Boiler, Heat Exchanger
The boiler or heat exchanger is overheating.
F.77 - Flue or Heat Exchanger Overheating
The flue or heat exchanger is overheating.
F.78 - Flue or Return Sensor Contact
There's a problem with the contact between the flue and the return sensor.
F.83 - Fault in Electronic Main Control
There's an issue with the electronic main control of the boiler.
F.84 - Flow Sensor Contact Fault
The flow sensor has a contact fault.
F.85 - Flow Sensor Fault
The flow sensor is not working correctly.
F.86 - Return Sensor Fault
The return sensor is not working correctly.
F.92 - Coding Resistor Fault
The coding resistor has a fault.
F.93 - Incorrect Configuration Coding
The configuration coding of the boiler is incorrect.
F.94 - Configuration Fault: Gas Family
The boiler's gas family configuration is incorrect.
F.95 - Configuration Fault: Gas Type
The boiler's gas type configuration is incorrect.
F.96 - Configuration Fault: Gas Controller
There's an issue with the configuration of the boiler's gas controller.
F.97 - Configuration Fault: Gas Quality
The boiler's gas quality configuration is incorrect.
F.98 - Configuration Fault: Flue Gas Configuration
There's an issue with the configuration of the boiler's flue gas.
F.99 - System Fault: External
There's an external system fault.
F.A1 - Pump Stuck or Running with Water Shortage
The pump is either stuck or running without enough water.
F.A2 - Pump Overloaded
The pump is overloaded.
F.A3 - Hot Water NTC Open Circuit
There's an open circuit in the hot water NTC
F.A4 - Hot Water NTC Short Circuit
There's a short circuit in the hot water NTC.
F.A5 - Tank NTC Open Circuit
There's an open circuit in the tank NTC.
F.A6 - Tank NTC Short Circuit
There's a short circuit in the tank NTC.
F.A7 - Hot Water NTC Sensor Fault
There's a fault with the hot water NTC sensor.
F.A8 - Break in Communication with IDM
There's been a break in communication with the IDM.
F.A9 - Tank or No Hot Water
There's either an issue with the tank or no hot water.
F.C0 - Unconfigured PCB
The PCB has not been configured properly.
F.C1 - PCB Error
There's an error with the PCB.
F.C7 - Incorrect Flame
The boiler has detected an incorrect flame.
F.d.0, F.d.1, F.d.8 - Service Functions
These codes relate to service functions of the boiler.
Are you interested in replacing your boiler and avoiding recurrent Vaillant Boiler Fault Codes and problems?
Here are some of the signs that you boiler needs replacing:
Noise
A sure sign that your boiler is due to be replaced is the kettling, gurgling and banging sounds that you might be hearing from your boiler when you run the hot water tap or turn on the central heating
Strange smells
While carbon monoxide does tend to be odourless, some gas companies do add a scent to help it become easier for you to detect if a leak has occurred. An eggy, sulphur-like smell around your boiler is a sure sign that there is a carbon monoxide leak and you should open all the windows and get out of the house as quickly as possible. Contact the Gas Emergency Services as soon as you can.
Yellow flame
A healthy boiler that’s working well should burn with a blue flame. However, if you’ve noticed a yellow flame on your boiler, this could be a sign of a serious issue such as a carbon monoxide problem. This gas is colourless and odourless and often, a yellow flame is the first sign that there’s a problem so it’s important to keep your eye out for it. If exposure levels are high enough, carbon monoxide can lead to serious illness or even be fatal.
Increase in energy bills
A boiler that is getting old and is increasingly less and less efficient can cost more money than most people can afford to spare. And, upgrading to a boiler that includes modern smart controls will not only improve efficiency but also give you a greater control over your energy usage and spending.
Frequent breakdown
Are you noticing that your boiler is break downing regularly or you are topping up your water pressure every week?
Reduced efficiency
When it comes to energy efficiency, some boilers are just missing the mark due to age. A boiler that’s rated ‘A’ in terms of efficiency will have an energy efficiency level of at least 90%. On the other hand, a boiler that’s rated ‘G’ will have an efficiency level of around 70%, meaning that for every £1 you spend on your energy bill, you’re losing 30p in wasted energy.
Expensive & difficult to find parts
If you’re having increasing problems with your boiler and you have been told by your boiler engineer that new parts are hard to find, it’s a clear sign that your boiler will probably need to be replaced soon. The older a boiler gets, the less likely it is that parts will be readily available. And if you’re struggling to find an engineer who is experienced with the type of boiler that you have, that’s even more reason to consider replacing it.