Vaillant
Incorrect Bypass / Plumbing Configuration
Softener allows hard water through during regeneration (no soft water bypass)
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Bypass valve incorrectly set, Softener installed in partial bypass configuration, Internal service/bypass seals misfitted, Cross-connection in plumbing
How to Fix / Troubleshooting
Safety: Isolate water before altering plumbing or valve positions.
Steps:
- Check bypass valve: Confirm that the Vaillant bypass is in the correct position according to the installation manual.
- Review plumbing: Trace inlet and outlet connections to ensure they are not reversed and that there is no unintended cross‑connection.
- Internal seals: If the control head has recently been serviced, verify that internal seals and spacers are correctly installed; misassembly can allow hard water through during regeneration.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Bypass Valve Assembly / Internal Seal Kit
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements