Vaillant Ecotec Plus 831 Problems

The Vaillant EcoTec Plus 831: A Synopsis

The Vaillant EcoTec Plus 831 is known for its general reliability, making it a popular choice for many households. However, as with any appliance, it can sometimes encounter issues. While some models have common faults like leaking rubber tubes and occasional diverter valve failures, the 831 is typically considered worth repairing when problems arise.

Common Issues and Solutions:

1. The F75 Fault:
   • Description: This is one of the most recognized issues with the model. The F75 fault can manifest when there’s dirt in the system. It may cause the boiler to malfunction or show errors, especially during temperature changes.
   • Solution: A proficient engineer should typically address the issue. It’s essential to ensure that the professional hired is adept at repairs since not all specialize in such tasks. A system power flush, though effective in certain cases, might not always solve the problem. The problem isn’t always with the pressure sensor being dirty but with areas behind it, which are slightly trickier to access. Regular maintenance and cleaning are key.
2. Potential PCB Issue:
   • Description: The PCB (printed circuit board) is a critical component of the boiler. Faults with this part can lead to various problems, including the F75 fault.
   • Solution: Engaging with service providers like British Gas on a fixed-price basis or directly with Vaillant can offer a cost-effective remedy. It’s also worth considering a fixed-price servicing agreement for ongoing maintenance.
3. Diverter Valve Seal Failure:
   • Description: If the diverter valve seal fails, it can lead to malfunctions in the heating or hot water system.
   • Solution: Regular checks and replacing faulty parts are vital. Ideally, these components should come out clean, indicating that dirt isn’t a contributing factor.
4. Low Flow Resistance:
   • Description: If the system has very low flow resistance, it may prevent the kick from the pump from being reliably detected, leading to the F75 fault, especially during temperature changes.
   • Solution: One can prevent the fault from occurring by manually shutting off about half of the radiators when cold weather is forecasted.
5. Temperature Differential:
   • Description: A low temperature differential, such as only 5-6°C, can contribute to the F75 fault.
   • Solution: Balancing to provide a higher differential may help. Adjusting each lockshield by a quarter turn can achieve this. As this reduces the average radiator temperature, it may be necessary to increase the flow temperature slightly to maintain the same heat output.

Seeking Assistance from Vaillant:

It might be worthwhile for users facing persistent issues to contact Vaillant’s customer service directly. Expressing concerns politely might lead to practical solutions, especially if the boiler is still under warranty. It’s essential to approach the conversation constructively to avoid placing blame solely on the manufacturer or the installer.

Conclusion:

While the Vaillant EcoTec Plus 831 boiler has its challenges, understanding these problems and their potential solutions can ensure that homeowners get the most out of their investment. Regular maintenance, periodic checks, and ensuring that the boiler is serviced by competent professionals can go a long way in ensuring its longevity and reliability.