F.46
FAULT CODE
Vaillant
Phase / Neutral Fault
High Severity
Engineer Required
The boiler has detected that the live and neutral connections are reversed. This is an electrical installation fault.
Step-by-Step Fix Guide
-
Step 1
Do not attempt any electrical work yourself
-
Step 2
This usually indicates a wiring problem at the boiler or spur
-
Step 3 Engineer only
A qualified electrician or Gas Safe engineer should check the polarity of the electrical supply
Gas Safe Reminder
Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.