046
FAULT CODE
Navien
Heat Exchanger Overheating (Auto-Reset)
Medium Severity
Engineer Required
Abnormal heat exchanger overheating — the boiler should auto-reset. If recurring, investigate circulation.
Step-by-Step Fix Guide
-
Step 1
Allow the boiler to auto-reset
-
Step 2
If 046 recurs, check system pressure and bleed radiators
-
Step 3 Engineer only
Call a Gas Safe engineer if the code keeps appearing
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.