18
FAULT CODE
Viessmann
Pump Blocked or Not Running
High Severity
Engineer Required
The circulation pump is not responding or is mechanically blocked. Water cannot flow through the heating system.
Step-by-Step Fix Guide
-
Step 1
A Gas Safe engineer will need to check if the pump is seized
-
Step 2
The pump may need cleaning, freeing up, or replacing
-
Step 3 Engineer only
Wiring to the pump should also be checked
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.