51
FAULT CODE
Viessmann
Flame Signal Present Without Gas Release
High Severity
Engineer Required
The ionisation electrode is detecting a flame even though the gas valve should be closed. This is a serious safety fault.
Step-by-Step Fix Guide
-
Step 1
Turn the boiler off immediately at the isolating switch
-
Step 2
Do not attempt to reset the boiler
-
Step 3 Engineer only
Call a Gas Safe engineer immediately — the gas valve may be leaking internally
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.